Volume 45, Issue s1

The 16-channels dense wavelength division multiplexing (DWDM) systems have been optimized by utilizing hybrid configurations of conventional optical fiber amplifiers (EDFA, RAMAN and SOA) and optical photodetectors (PIN, APD(Si) and APD(InGaAs)). The DWDM systems were implemented for 5 Gb/s channel speed using one of these configurations with 100 GHz channel spacing and 25 km amplifying section. The hybrid configurations are the combinations of (PIN + EDFA), (PIN + RAMAN), (PIN + SOA), (APD(Si) + EDFA), (APD(Si) + RAMAN), (APD(Si) + SOA), (APD(InGaAs) + EDFA), (APD(InGaAs) + RAMAN) and (APD(InGaAs) + SOA). Based on BER, Q-factor and eye diagrams, the performance was compared for these configurations under influences of various thermal noise levels of photodetectors over different fiber lengths ranging from 25 km up to 150 km. The results revealed that both APD structures give optimum performance at input power P in  = 5 dB m due to high internal avalanche gain. EDFA outperforms RAMAN and SOA amplifiers. SOA amplifier shows degraded performance because of nonlinearity effects induced. RAMAN amplifier seems to be the best alternative for long reach DWDM systems because it minimizes the effects of fiber nonlinearities. The configuration (APD(Si) + EDFA) is the most efficient and recommended to be used for transmission distance beyond 100 km due to its larger Q-factor.

This study has outlined the effects of physical parameters of erbium doped fiber amplifier (EDFA), semiconductor optical amplifier (SOA) on the performance of amplified soliton transmission systems. Injection current-based SOA, EDFA length is taken into account. It is observed that the optimum soliton power and signal per noise ratio are achieved with 5 m EDFA length and 900 mA injection current-based SOA. As well as the bit sequence variations based user defined bit sequence generator are employed in order to measure the soliton transmission system performance. The signal per noise ratio is enhanced with 4 bit sequence. Soliton peak power, output soliton power, and maximum Q-factor are optimized with 8 bit sequence for soliton propagation length of 150 km and possible transmission data rates of 160 Gb/s. Improvement percentage ratio in soliton peak power by using two amplification techniques a long propagation length is deeply stimulated with optiwave simulation program.

Long-haul 16-channel dense-wavelength division multiplexing networks employing two different avalanche photodiode (APD) structures (Si and InGaAs) and positive-intrinsic-negative (PIN) photodetectors are simulated and compared under thermal noise effects for different fiber lengths. The effect of thermal noise level on the transmission quality with a variation of amplifying section length, number of amplifying sections and channel speed is discussed. The impact of thermal noise on the system performance is analyzed by varying input power from −5dB m to 20dB m for both 25 km and 50 km amplifying section at 100 km fiber length. The performance is evaluated for both 5 Gb/s and 10 Gb/s data rates over transmission distances up to 500 km. A comprehensive comparison is developed based on signal-to-noise ratio (SNR), quality factor ( Q -factor) and bit error rate (BER). It is found that both APD structures achieve superior performance up to distance of 350 km comparing to PIN photodetectors for 50 km amplifying section. The system provides optimum performance at input power P in  = 10dB m in case of 50 km amplifying section, but then afterwards, the performance is degraded rapidly due to nonlinearities. The results revealed that the worst performance scenario is at 10 –18 W/Hz thermal noise in terms of higher BER and lower Q -factor. Finally, the desirable BER of 10 –12 is achieved at Q -factor of 6.78 and SNR of 23 dB.

The most powerful computer is in a very big need for a reliable random access memory (RAM) which can buffer digital data in. All optical RAM design is introduced in three phases. Those are the loading process phase which describes how data will be entering the closed trap from the line bus. The regeneration process phase which describes how data trapped are regenerated to not to lose its power or get a distortion. As well as the recalling process which describes how trapped data be handled to the line bus is also introduced.

Wavelength division multiplexing (WDM) is a very important technique to utilize the bandwidth of optical fiber; multiple channels can be transmitted in the same fiber cable at the same time, and each channel has individual wavelength. At different network node, it’s required to add or drop wavelength, wavelength converter process is a technique responsible for converting the wavelength of signal to other wavelength up or down from the original value. This paper has presented a proposed model to generate inverted and non-inverted wavelength conversion by using single wide band traveling wave semiconductor optical amplifier (WBSOA), based on cross-gain modulation. The investigation of conversion efficiency ( η ) and quality factor ( Q ), versus pump power ranged value from −30 to 0 dB m, and input signal power is 0 dB m with data rate 25 Gb/s, are studied for up and down-wavelength conversion, “co-propagation” and “counter-propagation”, respectively. The simulation results indicate that, to get maximum conversion efficiency and maximum quality factor by using single WBSOA, the pump power should be located between −30 to −20 dB m for maximum conversion efficiency and equal to −10 dB m for maximum quality factor, that for up- and down-wavelength conversion, co-propagation and counter-propagation.

This study presents the polar polarization mode and average radical intensity flux distribution measurements based on all optical spatial communication systems. The numerical technique that is applied with the simulation model is the diffraction fast Fourier integral transform. Spatial optical sources are used such as continuous wave (CW) laser and vertical cavity surface-emitting laser (VCSEL) with spatial connector and spatial aperture. Spatial temporal polarization effects are taken into account. Percentage encircled flux/average flux radical intensity and polar radical polarization are measured with spatial connector distance and spatial aperture width. The encircled flux is constant at 95 % of its value in the case of VCSEL laser source at a radical distance of exactly 10 μm. However, the encircled flux is constant at 92 %of its value in the case of CW laser source at a radical distance of exactly 6 μm. It is noticed that the encircled flux increases with increasing radial distance of spatial apertures that are used with two suggested light sources. The encircled flux is constant at 93 % of its value in the case of VCSEL laser source at a radical distance of exactly 10 μm.

A U-shape cavity including the microring resonator with a radius of 3 µm has been modeled and studied for the throughput and drop output power enhancement of the microring resonator. We have obtained the maximum output power of the silicon microring resonator by varying the bandgap between the microring and the coupled bus waveguides. The outputs can be further affected by using the different semiconductor materials such as GaAs and InAs as core waveguides, which show significant power enhancement at the throughput and drop, respectively. A time delay of 347 fs is realized for the generated results, which is occurred due to the different light propagation patch.

This paper has outlined high-speed transmission circuits signaling in guided or unguided optical communication systems. An efficient prediction scheme to predict the signal distortion caused by intersymbol interference. As high-speed digital signals exceed many gigabits per second speeds, eye diagrams provide the means to quickly and accurately measure signal quality and system performance. Semiconductor understands the capacitance constraints that designers are faced with when using these high-speed interfaces and offers a wide line of ultra-low capacitance electrical spectral density protection devices that service these interfaces, and the noise can be reduced at the optimum circuit at both bandwidths of 167 MHz, and bandwidth of 200 MHz.

The study outlines the different types of electro-optic filters that are used in fiber optic access transceiver systems. These filters are classified into the electrical filter in the receiver side and optical filters are located between fiber optic and transmitter. The optical filters are, namely, Fabry Perot, Gaussian, and Bessel filters. While electrical filters that are namely low pass Bessel, low pass Gaussian, and low pass squared raised cosine roll-off filters. The study emphasizes the important criteria in the employment of electro-optic filters in this system for signal fast processing. The Fabry Perot optical filters in addition to low pass squared raised cosine roll-off filters are clarified the best-obtained results in the comparison with other proposed filters.

This work outlines technical specifications of the undersea fiber optic communication channel bandwidth, capacity with taken into account the maximum and minimum extended fiber cost in the presence of amplifiers stations. The number of amplifiers in the amplification stage are addressed based on the amplifier distance to strength the light signal in water depth after 5 km distance. The fiber channel capacity is estimated at different water depth and at the surface of the water. Minimum input signal power and required detectable received power are adjusted to ensure the high data rates in submarine cable systems under the best and worst conditions of the seawater pressure. The study emphasizes the high data rates transmission can be achieved at a distance of 10 km depth.

This paper has simulated the pump laser automatic signal control for erbium-doped fiber amplifier gain, noise figure, and output spectral power. Signal gain and noise figure are deeply studied in relation to laser pump power variations at operating pumping wavelengths of 980 nm and 1,480 nm for previous and proposed models. Similar to the study of the light signal to noise ratio, output power level and maximum Q factor are also simulated versus EDFA amplifier length at pumping power of 500 mW and different pumping wavelength by using the proposed model. The obtained results are better by using a pumping wavelength of 1,480 nm than a pumping wavelength of 980 nm. The optimum EDFA amplifier is 5 m, which gives better performance than other amplifier lengths.

The study has outlined the different correction codes based optical wireless communication channel and security management in free space optics communication systems. The used codes that are namely forward error correction (FEC) code, Reed Solomon (RS) code, and Redundancy check (RC) code. The output power, maximum Q-parameter coefficient and minimum data error rates are estimated with these codes with variations of input signal power and propagation distances. The performance of optical wireless channel is enhanced with FEC code in compared to other proposed codes under the same operating conditions.

This study clarifies the comparison between hybrid all optical fiber amplifiers in single-stage and multi-stage amplification. EDFA/Raman, Raman/EDFA/Raman, and EDFA/Raman/EDFA configurations are employed for upgrading optical communication systems. Single-stage Raman amplifiers clarifies very better performance than single-stage EDFA amplifier. Multi-stage Raman/EDFA/Raman also outlines very better performance than other hybrid configuration up to 475 km distance. Single-stage Raman amplification has outlined maxi. Q factor up to 218.392 for 250 km distance and 11.937 up to 475 km propagation range. So hybrid all optical amplifiers are essentially for upgrading optical system performance efficiency.

This study presents an analytical model analysis of reflection/transmission characteristics of long-period fiber Bragg grating (LPFBG) by using coupled mode theory. Reflected signal power is deeply studied against grating length at the optimum operating signal wavelength of 1550 nm for the proposed and previous models. Reflectivity and transmission coefficient are also clarified versus operating wavelength for the previous model and proposed a model with a central wavelength of 1550 nm, Δ n  = 0.003 and optimum grating length of 30 mm. In the same way, the reflectivity and transmission coefficient are outlined against relative refractive grating difference step at the optimum wavelength of 1550 nm and optimum grating length of 30 mm. The optimum LPFBG can be achieved with the optimum grating length of 30 mm, operating wavelength of 1550 nm and relative refractive grating difference step of 0.3 %.

This work clarified the conventional/phase shift dual Mach–Zehnder modulation measured technique for upgrading radio over fiber (ROF) systems. Four levels of pulse amplitude modulation and non-return to zero code scheme are employed in different previous studies for upgrading ROF systems. The possible transmission distance is extended to 150 km and a bit rate of 40 Gb/s for achieved acceptable max. Q factor of 13.7498 and minimum bit error rates of 1.82×10 –43 . The total optical received power is measured at fiber cable length for maximum distance. Also, in the same way, the signal power levels are measured after fiber optic cable and avalanche photo detector optical receiver. The proposed model has presented the enhancement percentage ratio of 13.654% over the previous models in signal quality enhancement.

This study has simulated the spatial optical transceiver system based on measured index multimode optical plastic fibers channel with 1 Tb/s in 1.5 km distance. These plastic optical fibers are simply step index polycarbonate, step index polystyrene, step index polymethylmethacrylate, graded index polymethylmethacrylate and graded index cyclic transparent optical fiber (GI-CYTOP). Maximum Q-factor, optical signal power at optical fiber channel, receiver sensitivity, and coupling coefficient for sample of modes are measured based on GI-CYTOP fiber for the comparison between the previous model and the proposed model. This study clarified the enhancement of both maximum Q-factor and receiver sensitivity even though at high signal losses. The optimized Q-factor and receiver sensitivity are obtained for various plastic optical fiber channels. Power intensity level of dominant mode–based GI-CYTOP fiber channel is measured. The proposed model has presented better performance based on GI-CYTOP fiber channel in maximum Q-factor, which is within the percentage ratio ranging from 45.65 to 53.26%, optical signal power is within the percentage ratio ranging from 32.87 to 44.77%, and receiver sensitivity is within the percentage ratio ranging from 6.3 to 12.26% than the previous model at transmission distance ranges from 500 to 1500 m and bit rate of 2.5 Gb/s. GI-CYTOP fiber clarified better performance in maximum Q-factor and receiver sensitivity response better than other plastic optical fibers channels.

The work has outlined the Fabry Perot laser properties with high pump lasers for upgrading fiber optic transceiver systems. The physical structures of the light source are taken into account such as active layer length and active layer width. High pump laser is used for providing strength to the signal through the transmission/reception stages. Peak and minimum signal power levels are measured in the spectral frequency domain and time domain. Signal amplitude level margin is also measured with the optimum physical parameters of the light source. The optimum operation system performance efficiency is achieved with an active layer length of 0.06 cm, and active layer width suitable is 1.5 × 10 −4  cm.

This study created a 13 Gb/s transmission speed per 300 channel dense wavelength division multiplexing system based on hybrid optical fiber amplifiers and filter techniques to enhance signal gain. The filter techniques used here included a hybrid optical amplifier, a gain flattening filter (GFF), a Fabry–Perot filter, a fiber Bragg grating (FBG), and glass composition technique. The techniques were combined to optimize signal gain as follows: the study began with an erbium-doped fiber amplifier (EDFA), added a Raman amplifier, added GFF, added fiber Bragg grating, added glass composition, and finally achieved a hybrid-modified model after adding Fabry–Perot filter. The signal gain was optimized with the hybrid-modified model via the different operating parameters of the EDFA. The proposed model also showed a better performance (30–40 dB greater) than the previous model (Mahran O, Aly MH. Performance characteristics of dual-pumped hybrid EDFA/Raman optical amplifier. OSA – Applied Optics Jan 2016;55:22–6) after changing the values of the signal wavelength, the EDFA, and the length of the Raman amplifier.

This work outlined the fast speed response and high modulation bandwidth through LiNbO 3 electro-optic modulators. The refractive index is analyzed to estimate the switching voltage and modulation bandwidth for these modulators. The modulation voltage and data transmission data rates are analyzed and discussed clearly through LiNbO 3 electro-optic modulators. The modulator’s performance efficiency is upgraded with the optimum modulator length of 10 mm and its thickness of 2 mm. The proposed modulators are compared with GaAs electrooptic modulators under various electro-optic modulators dimensions at 1300 nm near-infrared region and room temperature.

Aim and scope of this study is to simulate the performance signature of optical inter satellite links based booster Erbium doped fiber amplifier (EDFA) and receiver preamplifiers. The study is simulated to demonstrated the effect of changing the propagation distances between satellites spacing based on the booster EDFA and receiver preamplifiers. Signal power amplitude, Max. Q factor, and min bit error rate are investigated against the input power variations.

This work clarified the performance enhancement of transceiver system based (IS-OWC) link by using both vertical cavity surface emitting laser diode (VCSEL) and continuous wave (CW) laser sources. The proposed model has been investigated and discussed. The inter satellite link has been modelled by using optisystem simulator at 10 Gb/s and 40 Gb/s for long distance up to 5000 km by using return to zero (RZ) and non return to zero (NRZ) schemes. The performance of IS-OWC system has been investigated by estimating the evaluation parameters such as Q-factor and bit error rate (BER). The results revealed that the NRZ is superior to RZ due to its reduced bandwidth. The BER obtained at 5000 km distance for NRZ scheme is 10 −12 and 10 −10 when using VCSEL and CW laser source respectively. The Q-factor records higher values at different distances when using VCSEL.

This study presents high speed optical switching gain based Erbium doped fiber amplifier model. By using the proposed model the optical fiber loss can be minimized. The system is stabilized with the power budget of 25.875 mW a long 75 km as a length of optical fiber in this study can be verified. The modulation rate of 10 Gb/s can be upgrade up to reach 30 Gb/s. The suitable power for the optical transmitter is −2.440 dBm and NRZ modulation code is verified. The receiver sensitivity can be upgraded with the minimum bit error rate and max Q factor are 1.806 e−009 and 5.899.

This work discusses the effect of wavelength division multiplexing on performance of intersatellite link. Intersatellite optical wireless communication (IsOWC) system is simulated by using OptiSystem software. Number of multiplexing channels involve on system performance. Bit rate is an operating parameter that determines the quality of the signal. Also, wavelength and distance between satellite transmitter and satellite receiver determine the system performance. In this article, the max Q factor, received power, and optical signal/noise ratio are the major leading performance parameters.

In this study, six different types of optical fibers (SMF, HNLF, HNL-DFF, NZDSF, LEAF (step core) and LEAF (ring core)) can be used for different number of channels (16, 32, 64, and 80) at different bit rates to calculate the quality factor for these types of optical fibers at the optimum length for max BER × 10 −9 and min BER × 10 −12 . By using the software Optisystem version 13, the work has been demonstrated and compared with previous study to find the best one under the same operating conditions.

This work demonstrates how to measure jitter using the eye diagram Analyzer histogram feature. Bit sequence generator is employed with the NRZ Pulse generator with the electrical jitter in order to measure the signal amplitude level. We have modulated the light signal from CW Laser with the electrical signal by Mach-Zehnder Modulator through 5 km fiber cables. The signal can be amplified with a gain of 7 dB with the presence of transimpedence amplifier. The combination of electrical signal and signal from noise source can be filtered by using the low pass Gaussian filter.

The work offered the analysis comparison study of optical wireless intersatellite link (ISL) for both different bit sequence generators and filters. The study clarifies the impact of varying sorts of both bit sequence generator (data source) in the transmitter and electrical filters in receiver on system performance. The two bit sequence generators used are pseudo random bit sequence generator (PRBSG) and user-defined bit sequence generator (UDBSG). The used filters in this study are low pass (LP) Bessel filter, LP Gaussian filter, LPCROF (cosine roll-off filter), and LPSCROF (squared CROF). Performance of the filter depends on the order of filter and filter bandwidth. The performance parameters in our study are quality factor, Bit Error Rate (BER), and optical received power. In this study, variation of optical received power depends on the type of sequence generator because it is measured after the channel directly.

This study has demonstrated the simulative and analytical methods of bidirectional EDFA amplifiers in optical communication links in the optimum case. The output power, max. Q factor and light signal/noise ratio variations are clarified with pump power variations at the bidirectional amplification EDFA amplifier for the previous/proposed models at optimum EDFA length of 8 m. As well as the output power and max. Q factor variations with EDFA amplifier length variations are demonstrated at the bidirectional amplification EDFA amplifier for the previous/proposed models at various pump power levels. The optimum operation efficiency case is observed at 8 m EDFA amplifier length and 120 mW pumping power.

This paper contains a main model which concludes a two optical fiber cable along 70 km and with Parametric/Raman amplifiers with a result of total power 0.781 dBm that computed by the optical power meter which is located before the receiver part and the second optical fiber channel, a total power −44.186 dBm at the end of model which is computed by the electrical power meter visualizer, and a max. Q factor 2.548 computed by the BER analyzer. The suggested model has outlined some updates on the previous model to improve the results so that the results are increased at the same length as the following: total power of optical signal becomes 10.039 dBm, total power of electrical signal becomes 0.624 dBm, and the max. Q factor becomes 9.60787.

This study presents fiber optic losses/dispersion and signals bandwidth measurements under high temperature and high dopant germanium ratios variations for ultra-long haul distances without amplification stage. The fiber losses, fiber dispersion, and total fiber data rates are estimated and compared with the previous results under room temperature and high germanium dopant ratios to silica glass fiber. Then the model is extended for ultra-fiber transmission distances up to 500 km under high-temperature variations without using any amplification stage. The fiber losses/dispersion coefficient is degraded, and the total fiber data rates are enhanced with the increment of high dopant ratios of germanium.

This study has outlined the performance analysis of the cascade traveling-wave optical amplifier (Semiconductor optical amplifier [SOA]) with multiplexing techniques based on fiber communication transceiver systems. The maximum Quality factor is measured against signal power. Signal input power level is enhanced by using the suggested model with previous model. The low pass Bessel filter removes the unwanted ripples from the original signal. The suggested model has clarified better performance efficiency than the previous model.

This work clarifies the gain/noise figure spectra of average power model Raman optical amplifiers in coarse wavelength multiplexed systems. The proposed model have a total received power of 16.306 dBm, signal gain of 21.68 dB, and noise figure of 3.802 dB at the same operation parameters of the previous model which operated at length 0.2 km at the optical fiber coarse wavelength division multiplexing (CWDM) and transmitted signal power is 20 dBm. So the updates help us to greatly improve the system.

This study presents the effects of Tx./Rx. pointing errors on the performance efficiency of local area optical wireless communication networks. The received signal power and max Q factor are measured in the presence of vertical-cavity surface-emitting lasers (VCSELs) bias current and modulation current at maximum propagation distance for the wireless network. The signal is enhanced with increasing of bias and modulation peak currents of the VCSEL device. The optimum received power and max. Q factor is also examined at Tx./Rx. the pointing error of 0.1 mrad and propagation reach of 5 km at available bit rates transmission of 10 Gb/s.

This paper simulates the bidirectional Er-Yb codoped fiber amplifiers (CDFs)-based DPSK modulation scheme for high speed fiber system capacity. The combination of Erbium-Ytterbium codoped fibers into a single fiber has been developed for the extension of the absorption bands for doped fibers. The signal gain variations versus pump wavelength variations have been demonstrated for various doped amplifiers with the proposed Er-Yb CDFs at amplifier length of 5 m. Also the signal gain variations versus pump wavelength variations have been illustrated for the proposed Er-Yb CDFs at 5 m amplifier length in different pumping configurations. The total optical power, max. Q factor, total electrical power, output optical signal/noise ratio, and signal gain variations versus fiber length variations have between simulated and clarified in the presence of bidirectional various lengths of Er-Yb CDFs.

This model in line and post erbium-doped fiber amplifiers with ideal dispersion compensation FBG for upgrading optical access networks for an extended distance of 60 km inside the optical fiber cable with a bit rate 10 Gb/s and Erbium-doped fiber amplifier (EDFA) which applied at length 5 m. The electrical results are measured by electrical visualizer (eye diagram analyzer, electrical power meter visualizer). The eye diagram analyzer used to calculate the min bit error rate in addition to the maximum Q factor which has a result in the proposed model is 51.97. The electrical power meter visualizer used in the proposed model to calculate the total power which has a result of 23.70 dBm.

Linear/Measured chirped Gaussian pulse propagation is simulated at various data rates transmission in the presence of group velocity dispersion without amplification unit. The power variations (PVs) vs. frequency, time period are also clarified after 250 km fiber channel length and 10 Gb/s bit rate (BR) of for Gaussian pulse generators with linear chirp factor of 2 rad/s, measured chirp factor (alpha parameter of 2 rad/W, Adiabatic chirp of 10 s −1 ). Moreover the overall total light power after fiber, the overall total electrical power after APD receiver are studied and clarified for Gaussian pulse generators with linear chirp, measured chirp factor. PVs vs. frequency, time period are simulated after APD receiver for Gaussian pulse generators with linear chirp, measured chirp factor. Maximum signal amplitude variations vs. time after APD receiver for Gaussian pulse generators with linear chirp, measured chirp factor are also clarified with the numerical simulation results.

This work outlines 80-channel wavelength multiplexing that has been developed with optimum length-based erbium-doped fiber amplifier (EDFA) with dispersion-compensated fiber. This paper has presented different fiber mediums with different effective areas such as single mode fiber (SMF), highly nonlinear fiber (HNLF), highly nonlinear dispersion-flattened fiber (HNL-DFF), nonreturn to zero dispersion-shifted fiber (NRZDSF) and a two types of large effective area fiber (LEAF Step core and LEAF Ring core) with dispersion-compensated fiber and EDFA amplification. Optimum fiber length can be obtained using minimum and maximum bit error rates with channels number and bit rate variations.

This study has simulated the raised cosine, linear, cubic measured pulses numerically with electrical jitter amplitude variations impact on fiber communication systems. The max Q factor, total electrical power variations against electrical jitter amplitude variations are demonstrated for various pulse configurations. The Q factor and signal power amplitude variations versus the time period with the spectral frequency are clarified based on various pulse configurations with an optimum amplitude jitter of 0.1 unit interval (UI). The total electrical power after the avalanche photodiode (APD) photodetector is measured numerically based on various pulse configurations with an optimum amplitude jitter of 0.1 UI.

The study simulated OQPSK modulation scheme-based FBG compensation for high data rates. The signal power, noise power and output power variations with the FBG length variations are clarified with fiber length of 50 km and amplifier gain of 40 dB. The max Q Factor variations with amplifier gain variations in the presence and absence of FBG device. The eye diagram analyzer for the proposed model under the same operating conditions with the previous model with/without FBG device. Besides the signal power variations is demonstrated against spectral wavelength and time variations for the proposed model with/without FGB device. Max Q and min error rate are clarified for the proposed model with 150 km length, amplifier gain pf 40 dB with FBG device length of 6 m and without FBG device.

This article discusses the performance of the free space optics (FSO) systems for short-range applications with the input signal power optimization. The BER eye diagram analyzer used to compute the optimum bit error rate and also compute the maximum Q factor for the previous and proposed models. The previous model has outlined the maximum Q factor of 206.45, where the proposed model Q factor value is 569.867 under the same operating parameters such as the wavelength of the transmitter of 1550 nm, the power of the transmitter of 10 mW, and the range of FSO is 800 m and signal attenuation 0.4 dB/km. The proposed study has outlined better performance than the previous study by about 21.76% enhancement percentage ratio.

The signal gain is improved by nearly about 15 dB by using the hybrid optical amplifiers technique. The gain flattened filter technique has outlined a larger value of signal gain than the hybrid optical amplifiers technique by about 17 dB whereas the Glass Composition method in the hybrid modified model has a better increase in the optimum value of signal gain that reached to about 70 dB. Fiber Bragg Grating (FBG) technique has outlined optimum gain value that is reached to about 50 dB. The combination of these techniques are used for the best optimized value of signal gain.

Article clarified the optimum fiber amplifiers length for wide band fiber system applications. Optical suppressed carrier transceiver with various fiber amplifier lengths in long haul applications is simulated by using optisystem simulation program version 13. Max. Q coefficient and min. BER can be tested for various fiber amplifiers lengths from 5 to 30 m. The optimum performance efficiency is achieved with 5 m amplifier length which the max. Q coefficient is 62.5 and bits error rate is tended to zero. Peak power amplitude level, noise signal power level, noise signal amplitude level (NSAL) and peak signal amplitude level after channel with a 45 km length for optimum fiber optic amplifier length of 5 m are measured.

This work presents the gallium arsenide (GaAs) electro-optic absorption (EA) modulators performance evaluation compared to the previous models with SiGe EA modulators under high-temperature variations. The average switching speed is studied and analyzed for both EAs. The consumed energy or power per bit is taken into account for both modulators. The modulation depth and transmission coefficient are studied for both previous and proposed EAs with 250 Gb/s at room temperature. The technical performance parameters are also analyzed such as insertion loss, modulation depth, output power, contrast ratio, transmission coefficient, and power length product for both previous and proposed EAs under high-temperature variations. The study assured that to get the optimum GaAs EAs performance efficiency, the modulator length and the thickness should be values of 50 and 5 mm, respectively at room temperature.

This work has reported the optical switches based semiconductor optical amplifiers (SOAs) for the performance of the characteristics enhancement by using various electrical pulse generators. Max. Q, bit error rate (BER) after light detector, max. signal power (MSP), min. noise power (MNNP), and total optical power after power combiner based SOAs with various pulse generators are simulated and clarified. Return to zero (RZ) pulse code has clarified max Q than other pulse generators. The max output signal power is improved with Gaussian pulse in compared to other pulse generators. Triangle/RZ pulse generators have presented better total optical power than other proposed generators.

The objective of the study is to simulate frequency shift keying (FSK)/amplitude shift keying (ASK) modulation schemes with raised cosine line coding based free space optics channel in clear weather conditions. The max. Q and optical signal/noise ratio (OSNR) with FSO channel length variations are simulated for the previous and proposed models at DRs of 10 Gbps, and also the max. Q factor with data rate (DR) variations is demonstrated for the previous and proposed models at 10 km FSO channel length. Max. Q , min. BER, signal power (SP), noise power, and total optical power (TOP) based FSK and ASK modulation schemes are illustrated through APD receiver with FSO channel length of 10 km.

This work has clarified the technical specifications and spectral performance characteristics of dispersion flattened fiber (DFF) in optical fiber systems. Effective nonlinear refractive index and first, second order polarization mode dispersion against spectral wavelength with fiber length of 1000 m and coupling length of 20 m are simulated and demonstrated. Total DFF fiber losses/dispersion performance parameters are investigated and simulated by using OptiFiber simulation. Zero DFF fiber dispersion and its dispersion slope are demonstrated clearly in details. The dominant modes and the cutoff data theoretical values based these modes for the proposed DFF fiber is determined and simulated in a clear manner.

This work outlined the integrated role between vertical cavity surface emitting laser diodes with Gaussian pulse generators and Ideal erbium doped fiber amplifier (EDFA) for the self-phase modulation instability management, as well as the signal/NP level (Power level [PL]) with the spectral frequency is simulated after wavelength division multiplexing (WDM) fiber at length of 10 km based third order Gaussian pulse generators. The light power variations against temperature after WDM fiber is also studied at length of 10 km based various order Gaussian pulse generators. Electrical received power (ERP) variations against temperature is clarified after avalanche photo diode (APD) photodetectors based various order Gaussian pulse generators. The study emphasis the bad effects of the increase of the temperature, and higher Gaussian pulse generators order on the signal power levels.

Radio over fiber (ROF) technique has been presented with hybrid ordinary modulation technology to achieve improvement in optical communication network performance. Fiber Bragg grating (FBG) is employed in single mode (SM) optical channel in order to enhance the transmission environment with dispersion compensation. The continuous phase frequency shift keying phase modulation (CPFSKPM) technique is included in this study. Both previous and proposed models have been inspected and investigated. Min. bit error rate (BER), max. Q factor, signal/noise ratio (SNR), received power (RP), and noise figure (NF) are the most essential parameters able to explain the behavior performance of optical communication network model.

Optical fiber coarse wavelength division multiplexing (CWDM) with erbium-doped fiber inline-amplifiers for the linear polarization geometrical model is studied in this paper for fiber system optimization by using the Optisystem simulation software. Signal gain (SG), noise figure (NF), and signal/noise are measured against CWDM optical fiber variations. The erbium-doped fiber amplifier (EDFA) is based on the Giles model which solves the steady-state rate equations for SG and signal absorption parameters with the cross-section area of the amplifier itself. The signal is optimized at EDFA length of 6 m, 10 Gb/s data rates (DRs) transmission and 10 km CWDM fiber optic length (FOL). Max. Q factor is degraded and min. BER is upgraded with both CWDM optical FLs and higher DRs transmission increase.

Effective role of optical duobinary transmitter with optical coherent quadrature amplitude modulation (QAM) receiver based on light amplifiers measured is stimulated by using optisystem simulation software version 13. Signal, noise power levels are stimulated after long haul fiber optic range up to 350 km distance. Measured light amplifiers, optical duobinary transmitters and optical QAM receiver are employed to measure the peak signal amplitude power (SAP) and noise signal power for bit rate transmission with 100 Gb/s based 350 km length. Maximum signal power level margin is enhanced with high data rates transmission.

The aim and scope of the paper is to simulate the signal propagation parameters estimation through designed multi-layer fibre with higher dominant modes by using OptiFibre simulation software. The multi-layer fibre profile has a length of 1000 m is designed and clarified with six layers. RI difference profile variations are clarified with radial distance variations. Modal/group index, group delay, dispersion, mode field diameter and total fibre losses are demonstrated with the fibre wavelength variations. All the dominant mode field distribution for multi-layer fibre are simulated and demonstrated. The other modes for designed multi-layer fibre with the theoretical fibre cutoff values for the different modes based the designed multi-layer fibre are analyzed and clarified clearly in details.

The study clarified spatial single mode laser interaction with measured pulse based parabolic index multimode fiber. Peak power level margin, maximum/minimum signal amplitude margin after parabolic index multimode fiber are measured with core radius of 25 µm, cladding thickness of 10 µm, refractive index peak of 1.4142, length of 300 m, and refractive index step of 1%. Maximum signal power margin against spectral frequency after PIN light detector based parabolic fiber properties is tested under the same operating parameters. The signal power amplitude/power within parabolic index multimode fiber is also measured based on variations of fiber lengths and relative refractive index step. The study implies the multimode graded index fibers with parabolic or near parabolic index profile cores have transmission bandwidths than other multimode fibers.

This study clarifies the data error rates optimization for OFC/OWC channels based on different transmission codes. These codes that are namely multi bits/symbol digital pulse interval modulation (DPIM), multi bits/symbol pulse position modulation (PPM), nonreturn to zero inverted (NRZI), 4 bit data symbol/5 bit code (4B5B), and Manchester for upgrading optical wired/wireless communication systems. The optical power through OFC/OWC channels, S/N ratio, the output power at the receiver side are stimulated with high bit transmission rates. The effects of coding complexity on the Q -factor, BER, optical power, and electrical received power are also stimulated using both DPIM and PPM coding.

This paper aims to simulate performance efficiency of carrier suppressed non return to zero line coding based FSO transceiver systems under light rain conditions with amplification units at 40 Gbps. The max. Q , BER and total optical power are simulated and demonstrated after FSO channel and PIN Photodetector Receiver under light rain weather conditions at maximum reach of 1.2 km at 10 Gbps. As well as the max. Q Factor variations versus max reach variations are clarified after PIN photodetector receiver under light rain weather conditions at 10, 40 Gbps with/without amplification units. Besides the total optical power variations versus max reach variations are assured after FSO channel under light rain weather conditions at 10, 40 Gbps with/without amplification units.

This article outlined intermediate/radio frequencies over fiber system performance efficiency measurement for the designed circuit frequencies. Output power, max. Q factor, and optical and electrical signal per noise ratio are also reported against radio and intermediate frequencies for the suggested system with the previous system. The suggested system has reported better efficiency and low loss flexibility than the previous system in the mentioned performance parameters. This study has clarified the low loss flexibility and high efficiency of radio per fiber system for modern wireless optical systems. We have clarified intermediate/radio frequencies over fiber system performance efficiency measurement in the presence of s and z parameters for the designed circuit frequencies. The comparison of the performance simulation parameters based on the previous/proposed models is clarified in the range of radio frequency and intermediate frequency range.

Passive optical network (PON) was designed in this paper. The design aim was to locate faulty line of service professionally without extra effort. In the literature, there were various PON-design methodologies. However, a design with fewer components and less faulty line tracking was a challenge. The suggested approach tried to overcome the leakage in the state-of-the-art, such that, the PON network would be able to serve forty-eight optical network units (ONUs). At the same time, the design has to have the capability to distinguish the dropped line of service straightforwardly. The design in this thesis mainly depends on the fiber Bragg gratings (FBGs) to create six-groups, in each group, there are eight-branches. Each branch serves as an end-user/customer point. The capacity of fault location was achieved for ONUs distanced/located as far as 20 Km from the central office (CO). There was only one optical spectrum analyser (OSA) inside the CO. This OSA employed to monitor the whole network groups, i.e., forty-eight branches/ONU were screened inside the CO to predict the fault location. The system is built using the OptiSystem software package version 14.

Raman optical amplifiers have more reliability than the repeater in the optical communication networks. In the optical amplifier, the transmission equals the gain bandwidth of the amplifiers. The optical amplifier has functionalities such as WDM amplification (gain equalization), gain control (rapidly variation of the gain), inter-stage access (compensation in the dispersion rate). This paper presents the optimum technical specifications of fiber Raman optical amplifiers (FROAs) with average power system for signal quality improvement in multiplexed systems. The signal has upgraded to a max. Q-factor of 11.47 applied along 1000 m as a range through the free-space optical (FSO) communication channel that has an attenuation rate of 10 dB/km. Our suggested system has clarified the best Q-factor that is greatly increased to reach 49.36 in the presence of the pump laser. The multiplexed communication systems signal quality is enhanced by the percentage ratio of 39.65%.

The aim of study is to simulate the impact of nonlinear cross gain modulation effects on optical transceiver communication systems with wide band traveling wave semiconductor optical amplifiers (WBTWSOAs). The max Q and electrical power against active amplifier length variations are simulated without/with nonlinear cross phase modulation (XPM) effect. We have been simulated the optimum Q Factor and BER at various data rate up to 160 Gbps with nonlinear cross phase modulation effect at the optimum active amplifier length of 300 μm. Also the optimum sig. power versus time and spectral wavelength is clarified with nonlinear CPM effect at the optimum active amplifier length. The total electrical power (TEP) and total optical power (TOP) are reported with nonlinear CPM effect at the optimum active amplifier length.

This study demonstrates the FWM nonlinearity effects on fiber systems based on conventional/linear/Lorentzian material gain wide band traveling wave semiconductor optical amplifiers (WBTWSOAs) at data rates of 10 Gbps. Max signal power (MSP) and noise power (NP) levels are illustrated versus time and SW after WDM multiplexer. The MSP and min NP are clarified against time and SW based conventional, linear, Lorentzian material gain WBTWSOAs. The total optical power after WDM multiplexer, and the total optical power based conventional, linear, Lorentzian material gain WBTWSOAs are measured. Max Q versus time after receiver based WDM multiplexer, and max Q versus time after receiver based conventional, linear, Lorentzian material gain WBTWSOAs are reported clearly in this study. Besides the max Q against CS is studied with/without FWM effects. Nonlinear coefficient, conversion efficiency is analyzed clearly against fiber length without/with FWM effects.

Free Space Optical (FSO) statement connection be a mark of view for the wire free connection among the lumps detached through a freehand intermediate so that the viewable and electromagnetic groups of the range are utilized as information transporter. The turbulence in an FSO link causes fluctuation in the intensity and the phase of the received signal. These fluctuations ultimately lead to the degradation in the link error probability and limit the system performance. This paper first focuses on survey of FSO system, modulation techniques used and environmental effects on link performance, while using different modulation techniques and turbulence models. In early days, it has been noticed that the vast renewal of investigation attention in this area possible to build FSO commercially feasible and observing into this prospect, information cadence approaches are one of the initial paths to improve connection feasibility. In this paper, we have applied the novel approach that is turbulence FSO for differentiation among OOK, BPSK, DPSK, and QPSK that has been analyzed. By comparison we found that BPSK approach is far better than all the other approaches in turbulence FSO connection. We use both theoretical analysis and MATLAB simulation to examine the BER performance. Here, the results have been mentioned for FSO system at different modulation format by taking values of the various parameters like: Data rate, Transmitter Wavelength, Aperture area, Transmitted power, Sigma. The contribution of the paper is to give a novel approach which is better than earlier approach in aspect of accuracy. The BER pursuance has been analyzed in aspect of distinct four approaches to remove the turbulence for its differentiation. The novelty of the system is that this paper analyzes the bit error rate of the FSO system using OOK, BPSK, DPSK, QPSK, and 8-PSK. It is appropriate as compared to the other systems it compensates lowest penalty rate as compared to other schemes that is why it is used for FSO turbulent system. This paper proposes adoptive transmission modulation technique gamma–gamma.

Elastic Optical Network (EON) is gaining a lot of attention these days because of its capability to dynamically utilize the network resources. It is possible to alter data rates in accordance with the required application by adjusting a number of spectrum slots which enhances spectral efficiency. However, it is difficult for new requests to access the usage of spectrum resources during the entire process especially when the spectrum is split into a number of small segments. Another key challenge in EON is to achieve effective routing and spectrum allocation. This entails looking for a specified route and identifying contiguous aligned spectrum slots for allocation to various requests. In this way, EON aims maximizing the connection while using the least amount of available spectrum resources. With this in mind, this research developed a first random fit (FRF) spectrum allocation technique that takes into account dispersion, which is a major physical flaw in optical networks. This scheme includes the effect of dispersion for the spectrum allocation approach. Using a FRF approach, this scheme tends to allocate a greater number of connection requests and spectrum is utilized in more efficient way. Starting with the lowest indexed slot, this scheme uses the First Fit algorithm and the less stable modulation technique like BPSK to search for and assign the spectrum slot. A random fit assignment strategy is used with a more robust modulation technique (QPSK) to exploit the next higher indexed spectrum slot which suffers larger dispersion effect. Longer light path requests are assigned to lower indexed spectrum slot (lower dispersion slots) using BPSK modulation technique, while shorter light path requests are sent to next higher indexed spectrum slot (greater dispersion slots) using QPSK modulation technique capturing the dispersion sensitive technique. The results show that the proposed technique achieves a minimal bandwidth blocking probability (BBP) of 0.048, Eye opening Penalty (EOP) of 45.45 dB and Quality Factor of 3.889 and B.P compared with other First Fit (FF) and Random Fit (RF) spectrum allocation schemes.

In this paper, all-optical 2-to-4 line decoder and read-only memory (ROM) are analyzed using a Reflective Semiconductor Optical Amplifier (RSOA) based optical switch. The structures of these 2-to-4 line decoder and read only memory are very simple and the operating speed is 200 Gbps, which can be used in optical hardware systems. The 2-to-4 line decoder output shows a very high extension ratio (ER), contrast ratio (CR), and Q value. These high values indicate the distinguishment between two states (‘1’ and ‘0’) very clearly.

A hybrid dispersion compensation module design, using Gaussian apodized fiber Bragg grating and 11 km long dispersion compensation fiber, is proposed for a 111 km long optical link. The proposed module is examined successively with four different chirping techniques. Further, the design is investigated thoroughly in pre-, post- and symmetrical-compensation modes. The performance characteristics of the optimized links are evaluated orderly by quality-factor (Q-factor) values, Eye-diagram and pulse width reduction percentage (PWRP). To further enhance the Q-factor value, optimal parameters of FBG are determined comprehensively by varying the effective refractive index and grating length values. The results show that the proposed dispersion compensation module using Gaussian apodized fiber Bragg grating works well for the quadratic chirping technique. The Q-factor values attained in pre-, post- and symmetrical-compensation modes are 40.5, 49 and 50, respectively, far higher than the values proposed in the literature to date. Thus the proposed technique is best suited for symmetrical and post-compensation modes. The workability of the proposed system is verified using OptiSystem software.

The primary objective of time wavelength-division multiplexing passive optical networks (TWDM-PONs) development at the moment is the cost-effective capacity acquisition. This work addresses this issue by demonstrating a full-system TWDM-PON was selected as a primary choice to NG-PON2 by Full-service access network (FASN) unanimously agreed and International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) G.989. An asymmetric TWDM NG-PON2 was demonstrated that provides 160 Gbps downstream and 80 Gbps upstream which is the target capacity by ITU-T G.989.1 based on OptiSystem-7 software. We propose to use fiber Bragg grating (FBG) and Er-doped fiber amplifier (EDFA) to reduced both of the chromatic dispersion effect and system attenuation until given permission to enhance the distance communication system. The proposed system’s performance is evaluated and compared with other works and ITU-T G.989.2 recommendations to demonstrate how the system can be enhanced in terms of capacity, link distance, bit error rate (BER), Q-factor and receiver sensitivity. According to the results, the optimum possible distance under communication requirements (6 for the Q-factor and 10 −9 for the BER) is around 65 km for the system with dispersion compensation. With the help of the low-cost directly modulated laser (DML) for uplink, we successfully improve the power budget to 41.2 dB along 65 km of bidirectional fiber at a 1:512 splitting ratio.

Security and privacy are two main dominant features of any communication system. In this paper, physical layer security of free space optical communication system using chaotic modulation scheme i.e., differential chaos shift keying (DCSK) is analyzed, where eavesdropper is actively present near the receiver and interfering between the transmission of secret messages from a transmitter to the receiver. In this manuscript, we have derived analytical expressions for the average secrecy capacity and secrecy outage probability which is used as a metric for secrecy performance analysis. The channel characterization is carried out using gamma–gamma model for weak-to-strong turbulence conditions. The effect of physical layer parameters like transmission link length, spreading length, etc. are considered for evaluating the security performance of the system. Numerical analysis is carried out and graphical results are presented. The results depicted that a very good average secrecy capacity can be achieved even in the presence of eavesdropper, however, it requires a tradeoff between high signal-to-noise ratio of main channel and large values of spreading factor. The proposed system is very promising for the future secured communication systems.

With the continuous maturity of the technology in the home network, the home network is developing towards intelligence, high-speed, sharing, remote and networking, especially the driving of multimedia services such as high-definition video, interactive games, and the development of intelligent terminals. The working frequency of access in the home network is gradually changing to the millimeter band, and 60 GHz in the millimeter band is considered to be a promising indoor high-speed access frequency band in the future. However, due to the small coverage and large transmission loss of millimeter wave, it can only meet the communication between terminals in a room. In order to meet the demand that users in the home network can access the network from any room for communication, researchers propose to use optical fiber to transmit wireless signals, which not only has low loss and large capacity, but also can transmit to any distance. PON technology has the advantages of high bandwidth, low loss, and easy maintenance. It requires a home network of PON and millimeter wave integrated access with the millimeter wave integrated network with high bandwidth, flexibility and strong penetration to meet the needs of high bandwidth, high flexibility and low loss of home network access. Therefore, it is necessary to study the home network scheme of PON and millimeter wave integrated access.

Today, communication is a crucial factor and requires a high data rate for transmission with in an error-free environment, so optical communication has emerged as a best solution to high-speed transmission systems due to its higher bandwidth and higher data rates. Fiber optic transmission integrating with some modern processing and modulator techniques are applied in various areas that need transfer of data from one point to another through reducing an optical affect. Coherent optical orthogonal frequency division multiplexing is a popular technique in optical communication today because of the excessive spectral efficiency, immune to interference, tolerance of the fiber dispersion and it is long-haul application. It employs the OFDM modulation method, which is a type of multicarrier modulation in which data statistics are distributed over a large number of low-cost subcarriers and is a solution to inter-symbol interference. Inter-symbol interference is generated by chromatic dispersion in high-speed optical transmission systems, and it is a severe issue in long-haul systems in the case of higher data rates transmission. The use of standard dispersion compensating devices, such as dispersion compensating fiber, does not completely compensate for high order dispersion, which includes third-order and high dispersion effects and also increase the loses of the system because it is a fiber in itself. This study proposes introducing the concept of coherent optical orthogonal frequency division multiplexing techniques in to the wave division optical network in the case of multiple users, high data rate transmission and long-haul and ultra-long-haul optical link to reduce the optical transmission on related issues and to improve the performance of optical network. The performance of the proposed network can be evaluated by using different parameters such as signal to noise ratio, bit error rate, optical signal to noise ratio, Quality factor and eye-diagram at different distance transmission up to 8000 km by using Optisystem software.

Modern optical communication heavily relies on coherent optical orthogonal frequency division multiplexing (CO-OFDM) modulation. But the usage of optical OFDM for fiber optic communication is still constrained in comparison to other modes of communication like visible light communication (VLC) and wireless communication due to a number of issues such as various sorts of fiber impairments including dispersion and attenuation. In this research paper, a novel optical OFDM modulation technique has been proposed. It is quadrature phase shift keying (QPSK) CO-OFDM modulation with Bessel optical filter in fiber optical link and is named as QCOB. This modulation technique works for optical fiber transmission. Its testing has been carried out for parameters like bit error rate (BER) and quality-factor (Q-factor) over a range of fiber length, fiber dispersion coefficient and input power. This modulation employs coherent optical OFDM with QPSK for subcarrier modulation. The optical link utilizes a Bessel optical filter. Improved results have been achieved over conventional QPSK CO-OFDM (QCO). The obtained results demonstrate the superiority of the QCOB technique in terms of performance enhancement and fiber impairment reduction. In comparison to the QCO technique, the BER performance (reduction in BER) of the QCOB technique shows an improvement of around 7.4, 100, 14.4, 46.4 and 3.4% for dispersion coefficient values of 10, 20, 30, 50 and 100 (in ps/nm-km), respectively.

The study has outlined grating index difference (GID) and grating order based distributed feedback laser effects on coarse wavelength division multiplexing optical fiber systems. Signal amplitude level (SPL), noise signal level are measured accurately based on various grating order of distributed feedback laser. Max. signal power (MSP), noise signal power (NSP) are also measured along the variations of frequency spectrum related to spectral wavelength and bit period time versus GID variations. The optimum signal power level and minimum noise power level, maximum SPL, minimum SPL are achieved with 0.1% GID and grating order of unity.

The work outlined ideal single mode laser operation with single measured drive phase shift/conventional Mach–Zehnder modulators (MZM) in optical access networks is simulated and analyzed. Maximum signal power level versus spectral wavelength and time domain spectrum after fiber channel based 1.5 splitting ratio conventional/phase shift MZM and Idea single mode laser is measured accurately. Maximum Q coefficient of 35.87 and mini bit error rates of 2.3279 × 10 −282 in the case of conventional MZM and idea single mode laser. Maximum Q coefficient of 17.86 and mini error rate of 1.0376 × 10 −71 in the case of phase shift MZM and Idea single mode laser.

This paper clarifies the effects of electrical filters with electro-optic modulators variations on the power/signal quality optimization and minimum data error rates reduction. The electro-optic modulators that are namely Mach Zehnder modulator, absorption modulator measured, single-drive Mach Zehnder modulator measured, and electro-absorption modulator. In addition to the filters are employed low pass (LP) Gaussian filter, LP Bessel filter, LP Butterworth filter, and LP Chebyshev filter. The hybrid combination between these modulators at the Tx. and the filters at the Rx. side give the chance to set the best candidate combinations from these devices for the power and signal quality optimization.

This paper clarified the optical fiber communication system links the performance signature for short-indoor applications. The electrical propagation delay time is investigated for copper links. The polystyrene optical link propagation delay time is also analyzed. The optical pulse broadening and the data transmission bit rates in the optical links are analyzed. The electrical/optical links performance is discussed with the variations of electrical/optical link variations and ambient temperature variations. The optical link performance efficiency has presented better performance than the electrical links, especially for short-indoor applications.

The paper reported the single fiber grating profile multi scan parameters for the optimization of the grating parameters by using OptiGrating program. The transmission/reflection spectrum of single grating fiber is reported versus variations of grating wavelength. Input–output pulse intensity of single grating fiber is clarified against the time span after the link length of 100 km. Fiber grating bandwidth, fiber grating side-lobes, fiber grating peak value and fiber grating pulse dispersion variations are clarified versus the scan parameter variations. The scan parameter can help the user in order to find the optimized grating parameters to meet the application requirements. As well as the optimized fiber grating amplitude/phase impulse response variations are outlined against the grating length variations.

This article has clarified ultralong reach and high data rate optical wireless multiplexing communication systems based on various modulation codes. Optical wireless communications can provide communication at high speed and achieve farther long distance compared to RF links. It is assured that the low bit rates can be used for long distance error-free transmission. The Q-factor decreases as the distance increases. The error at the receiving station increases with increase in transmission distance. Higher antenna aperture can achieve long distance transmission. The simulation results presented ultralong reach high speed date rates by utilizing VCSEL light sources and APD receivers. The optical signals with low bit rates can be used for long transmission reach. The performance of OWC link can be improved by using VCSELs and APDs. Therefore, the distance reach can be extended to 5000 km. The Q reduces and BER increases as the data rate increases for both NRZ and RZ schemes over various transmission reach on different temperature and various aperture diameters.

In this paper, an all-optical 1 × 4 demultiplexer (DEMUX) has been designed by employing 2D photonic crystal (PhC) waveguides for use in optical networking and signal processing. The proposed structures consist of four T-shaped and one Y-shaped waveguide using 15 a  × 15 a rectangular lattice silicon rods in ambient air. All-optical DEMUX has been simulated using the finite-difference-time-domain (FDTD) method and the results have been verified by distributing the optical field at a wavelength of 1.90 μm. Analysis of the device has been carried out for distinctive crystal and lattice designs with the achievement of a transmission ratio of more than 2.05 in presence of select input.

This work clarified the engagement of both nonlinear XPM/XGM in conventional band applications with the wide band traveling semiconductor optical amplifiers (WBTWSOAs) for passive optical network applications in downstream directions. The max. Q, total output power versus up/down wavelength conversion by using cascaded XPM with XGM at 10 Gbps are simulated. Besides, the max. Q Factor, conversion efficiency, and total optical power (TOP) variations are clarified in relation to bit rate variations for cascaded CPM&XGM and CPM, XGM stages. Moreover, the enhancement percentage ratio (EPR) in Q factor and TOP are analyzed and demonstrated versus bit rate variations for cascaded CPM&XGM stage over both CPM stage and XGM stage. The study emphasized the network reach can be extended to 80 km with available maximum data rates up to 250 Gb/s with power budget of 28.65 dB based on the cascaded CPM&XGM technique.

The work clarified the empirical laser measured with optical coherent quadrate amplitude modulation receiver for upgrading fiber optic systems. Peak signal amplitude and output power spectrum are measured after light receivers under the control of extinction modulator ratio, radio frequency switching voltage and switching bias voltage. The better the fiber optic system performance can be achieved with the higher values of extinction ratio, both switching radio frequency and bias voltages based LiNb modulators.

This paper has clarified the positive and negative effects of 3.1% germania and 1% fluorine DS fibers in multi-mode silica profile. The group delay and the total fiber dispersion against operating wavelength for PS and various doped silica (DS) fibers are demonstrated and assured by using OptiFiber simulation. The material, waveguide and total fiber dispersions are demonstrated against wavelength for the PS fiber, 3.1% germania DS (GDS) fiber and 1% fluorine DS (FDS) fiber. Besides the mode field diameter, fiber material loss, fiber bending loss and the dispersion group delay are simulated and clarified against the operating wavelength for PS and different DS fibers. The study gives the effects of the dopant ratio of germania and fluorine on the zero dispersion wavelength shift and DS.

The optical network plays a vital role in the current technology for providing high-speed data communication, which the networks operate at Tb/s. In this case, different modulation techniques can be used for different line rates to achieve high-speed data transmission. The light paths and various data rates such as 10, 40, and 100 Gb/s are the important parameters for mixed line rate networks. The wavelengths and line rates are powerful tools for mixed line rates networks. It can exist on different optical fibers. In this paper, advanced modulation techniques achieve a relative performance with the required Q-factor. This paper analysis for different matrix computations to achieve a superior Q-factor. It can affect the data rates and quality of transmission. This paper also proposed an algorithm that can improve the Q-factor. Q-factor is analyzed and proposes routing and wavelength assignment (RWA) techniques based on the Q-factor obtained at different line rates. This paper is a brief overview of a quality-aware path-finding algorithm for mixed line rates WDM/DWDM networks are present and discussed.

In the present work, nonlinear ring resonator based on two-dimensional hexagonal photonic crystal structure is designed for all optical OR and NOR gates in the wavelength range of 1355–2053 nm. The OR and NOR gates are made up of four optical waveguides which are critically coupled to a nonlinear ring resonator. The electric field distribution and photonic band gap characteristic of the proposed gates are solved by Maxwell equations using finite difference time domain and plane wave expansion methods, respectively. Simulation results by finite difference time domain approach show the minimum contrast ratio of 12.04 and 11.81 dB for OR and NOR logic gates, respectively. Also, the minimum delay time is obtained 1 ps for OR and 1.5 ps for NOR logic gates.

Free-space optical (FSO) wireless sensor network is rapidly growing for underwater communication applications. However, the high-energy loss and propagation distance are the key concerns during data transmission in SDN-enabled underwater wireless sensor networks (UWSNs). In addition, long-distance free-space data transmission in UWSNs relies heavily on FSO communication. Thus, FSO communication is integrated with SDN-enabled UWSNs to maximizing the network lifespan called SDN-enabled free-space optical underwater wireless sensor networks (FSO-UWSNs). Furthermore, clustering and routing can effectively balance the network load for energy-efficient data delivery in SDN-enabled FSO-UWSNs. However, choosing the optimal control nodes (CNs) in clustering is considered as an NP-hard problem. Accordingly, self-adaptive genetic approach-based particle swarm optimization (SAGA-PSO) is proposed as a cluster-based routing to optimize the CNs in heterogeneous SDN-enabled FSO-UWSNs. The proposed hybrid model of metaheuristics and genetic mutation, in which the native PSO is amended with the self-adaptive inertia weights and genetic mutation operation to identify the CNs based on genetic diversity dynamically. In addition, a novel fitness function is proposed to balance the cluster size by considering the most significant parameters like energy and distance of network devices. The SAGA-PSO is simulated using the ns-3 simulator, and SDN policies are controlled via the ONOS controller. Moreover, the proposed nature-inspired SAGA-PSO approach outperforms the existing state of arts by considering the performance metrics such as; alive nodes, stability period, average residual energy, the packet transmitted to CS, average delay, and fitness value.

Since the last two decades free space optical (FSO) communication transcends the RF communication and microwave systems because of its capability of carrying high bandwidth, license-free, long-range, small size, high bandwidth, low cost and ease of deployment. FSO communication has few limitations as well like beam dispersion, scintillation, weather effects etc. This paper demonstrates the implementation of FSO link and analysis of transmission performance of FSO channel for broadband access networks. The proposed FSO link is simulated in opti-system to analyze the physical characteristics of transmitter and receiver. The transmission performances of FSO link are validated using on/off keying (OOK) and differential phase shift keying (DPSK) at various atmospheric conditions with different data rates and transmission ranges. The transmission performance of the FSO link is analyzed under the influence of key parameters like launch power, beam divergence, atmospheric attenuation, receiver sensitivity and receiver aperture. The proposed model of the FSO link is investigated using key parameters like optical signal to noise ratio (OSNR), noise figure and bit error rate (BER).

This study presented design and analysis of high-speed data optical fiber communication system through EDFA amplifier system. The design with practical data for parameters to maximize the transmission bit-rate is clarified. The bit rate distance product can be optimized for the improvement of performance of high-speed long haul repeater spacing with amplification technique. The basic amplification system for optical fiber communication system is clarified. Transmitter/receiver components with the circuit connections and the operation are also indicated in details. The practical circuit model of the transmitter and receiver are designed clearly in this work. The design of distribution maps to measure the Q factor and minimum bit error rate and many different simulation models for applied to achieve high-speed data optical fiber communication system.

This paper simulated the different mode operations based all optical fiber amplifiers with optical differential polarization quadrature phase shift keying transmitter. Gain mode operation, power mode operation and saturation mode operation based all optical fiber amplifiers are employed to measure the signal power, noise power level at both spectral time domain and frequency domain. The peak signal power and signal power amplitude are accurately measured for different mode operations based all fiber optical amplifiers. The performance is enhanced with saturation mode operation based all optical fiber amplifiers.

This work has demonstrated the performance characteristics of single Bragg grating fiber under various filter impulse functions and grating filter profiles. Single fiber Bragg grating (FBG) power propagation, grating index change, coupling coefficient and apodization variations versus grating length variations is demonstrated at the central wavelength of 1550 nm by using both Hamming, Blackman impulse filter function and Hamming, Blackman grating profile. As well as the single FBG power spectrum, delay, dispersion, transmittivity/reflectivity are simulated and clarified against wavelength variations using both Hamming, Blackman impulse filter function and Hamming, Blackman grating profile. The Hamming impulse function filter and Hamming grating profile have clarified better performance than Blackman impulse function filter and Blackman grating profile.

Data rates in fiber optic communication (FOC) technology are highly increased and optical communication technology has been mostly advancing highly. There are different multiplexing techniques like frequency-division multiplexing (FDM), time-division multiplexing (TDM), wavelength division multiplexing (WDM), dense wavelength division multiplexing (DWDM), code division multiplexing (CDM), and digital coherent technology by using single mode fiber (SMF)/single core fiber (SCF), and using these multiplexing did not produce over 100 Tbps/fiber because of many factors like linearity and nonlinearities of fiber optic. To transmit a high capacity over 100 Tbps/fiber and long-haul transmission, the multiplexing techniques that are needed to break this bottleneck/capacity limit are termed space-division multiplexing, which uses single mode fiber (SMF) and multicore fiber (MCF). The target of this paper is to enhance the capacity of FOC systems using space-division multiplexing (SDM). The result produced during this paperwork is that the capacity enhanced is around 14.75 pb/s/fiber, after it is decreasing and thus the haul of transmission is 250 km with usable wavelength C + L band. The signal/noise ratio is 35 dB in FOC using single mode fiber (SMF) and multicore fiber (MCF). Finally, the SDM includes a great role in fiber optic just in case of effective information transmission by enhancing capacity, reduction of loss, distortion, cross talk, and power consumption reduction during information transmission; SDM in fiber optic is incredibly essential for effective communication systems with extremely high capacity and long haul transmission.

Aiming at the link length enhancement in intersatellite optical wireless communication (IsOWC) system, considering the hybrid radiofrequency (RF)-enabled multi input multi output (MIMO) system, we accentuate the realization of medium earth orbit (MEO)-based IsOWC system by incorporating different modulation formats such as return to zero (RZ), non-RZ (NRZ), and Manchester coding. A 40 Gbps and 16 × 8 MIMO system enabling 40 GHz RF signal is proposed by using even linear polarized (E-LP) mode, and odd linear polarized (O-LP) mode over a 22,000 km IsOWC channel. Further, a performance comparison of NRZ, RZ, and Manchester coding is performed at different IsOWC distances in terms of the Q factor. Results revealed that the proposed system with Manchester coding and O-LP mode can successfully cover the 22,000 km IsOWC link length by exhibiting a 6.35 Q factor value.

In visible light communication (VLC), intensity modulation with direct detection (IM/DD) based on DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM) is used to transfer data at a high rate. Because OFDM signals are modulated using IM/DD, the peak of the transmitted signals is scaled up, resulting in a high peak-to-average power ratio (PAPR). In this article, the Walsh–Hadamard transform (WHT) is used as a precoder for discrete Hartley transform (DHT) to decrease the PAPR and the DC bias and achieve a good bit error rate (BER) performance in such a system. PAPR reduction results from the decrease of superposition of the transmitted signals owing to the use of WHT as a precoder. The proposed scheme and conventional DCO-OFDM indoor VLC system based on discrete Hartley transform (DHT) are compared to assure the new system’s benefits and efficiency.

The effect of numerical aperture and doping concentration of thulium on the gain of TDFA with a single pump is investigated in this paper. Thulium doped fiber length of 10 m is analyzed for commonly used optical pumps of 1050 nm, 1560 nm, 1700 nm, and 1740 nm wavelengths with a power of 100 mW. Also, the thulium concentrations of 15.6 × 10 24  m −3 , 20 × 10 24  m −3 , 30 × 10 24  m −3 , and 40 × 10 24  m −3 , and numerical apertures of 0.3 and 0.4 are tried for each pump wavelength. It has been found the conventional 1050 nm pump is the least efficient. And in all the cases, the 0.4 numerical aperture is resulting in better gain as compared to the numerical aperture of 0.3. The results in terms of gain are compared for all pumping cases. It is observed that the highest gain of 28.27 dB is obtained at 1830 nm wavelength using pump wavelength of 1740 nm when the doping concentration of 40 × 10 24  m −3 and numerical aperture of 0.4 is selected.

In this paper, impact of thulium doped optical amplifier with RAMAN-EDFA hybrid optical amplifier (HOA) has been evaluated for super dense optical communication. Further, suitable power amplification has maintained with the support of proposed triple pump power of 1050, 850, and 800 nm for getting the desired outcome in terms of gain and noise figure for the transmission distance of 150 km.

Peak-to-Average Power Ratio (PAPR) is one of the major limitations of an Orthogonal time frequency space (OTFS) signals. To reduce the PAPR, a simple non-linear companding transform is proposed in this paper. The proposed companding transform mainly compresses the large amplitudes and slightly enhances the small amplitudes such that the peak power reduces but the average power remains unaltered. To validate the proposed companding transform, we compare the our proposed companding with the orthogonal frequency division multiplexing (OFDM), normalized μ − law, and clipping methods. Simulations demonstrate that, the proposed companded OTFS transform provides better PAPR than the proposed companded OFDM, μ − law companded OTFS and clipping methods.

For this research article, we have completed the comparative performance analysis of 128 × 40 Gbps DWDM long-haul system for the ultra-transmission capacity of 5.12 Tbps using CSRZ modulation format under the impact of Kerr’s nonlinearities with symmetrical, post and pre dispersion compensation techniques. The BER, Q-factor values and eye-diagrams are considered as performance metrics for the different power levels ranging from −4 to 8 dBm and various transmission distances with the increment of 2400 km. We have used Gaussian filters (GFs) before multiplexing and after de-multiplexing for ensuring channel separation to evade the inter-symbol interference and cross-talk. The graphical performance analysis of the proposed system has also been made with the above mentioned compensation techniques at 4, 6 and 8 dBm input powers using DCF at 50 GHz frequency spacing for the optimization of the used format. It is observed that overall, symmetrical compensation gave better-quality performance at all the power levels in comparison to pre and post schemes. Due to narrow optical spectrum of CSRZ format, the proposed system has shown consistency, resilience and toughness against the bottlenecks appeared as dispersion and nonlinearities. It has supported the transmission distance of 19,200 km at 6 dBm optimum power for symmetrical compensation with BER of 8.65E-13 against Q-factor value of 7.00 as compared to pre compensation for 14,400 km at BER of 2.28E-13 with Q-factor of 7.18 whereas post compensation technique have shown a transmission distance of 16,800 km at 8 dBm optimum launched power with BER of 1.63E-12 and Q-factor value of 6.92.

This paper deals with expressions for simple but precise analyses of fractional modal power (FMP) inside the core of optical fibers, the excitation efficiency and the normalized group delay (NGD) for the first higher order (LP 11 ) mode in step and parabolic index fibers both with and without Kerr type non linearity. To get the analytical results, we have employed simple power series Chebyshev expansion for the LP 11 mode of the above mentioned fibers. At first, the analytical expression for linear case is found out and then by applying the method of iteration the propagation parameters are estimated when there is nonlinearity of the Kerr type. Here, some typical step and parabolic profile fibers have been used for our investigation. Our findings of confinement and group delay parameters perfectly match with the precise numerical findings made by the intricate finite element method (FEM). This implies the precision of our formalism. The study of nonlinear optical transmission systems will benefit from the findings.

This research aims to investigate and improve multi-user free space optic systems (FSO) based on a hybrid subcarrier multiplexing spectral amplitude coding-optical code division multiple access (SCM-SAC-OCDMA) technique using MS code with a direct decoding technique. The performance is observed under different weather conditions including clear, rain, and haze conditions. The investigation includes analyzing the proposed system mathematically using MATLAB and OptiSystem software. The simulation is carried out using a laser diode. Furthermore, the performances of the MS code in terms of angles of bit rate, beam divergence and noise are evaluated based on bit error rate (BER), received power, and transmission distance. The performance of the MS code-based system was subsequently compared with Khazani Syed code (KS), multi-diagonal (MD), and modified quadratic congruence code (MQC) codes under different weather conditions at a bit rate of 1 Gb/s and BER threshold of 10 −9 . Heavy rain indicates the worst performance in terms of transmission distance of 0.9 km. Nevertheless, the system designed using the MS code outperformed the KS, MD and MQC systems as it is capable of supporting up to 6.3, 0.8, 0.9, and 1.5 km, respectively, under clear weather. In conclusion, this study provides a means of improving FSO communications that suits tropical and Malaysia weather conditions.

All-optical half adder using quantum dot semiconductor optical amplifier is proposed and analyzed using numerical simulations for two different unsaturated gains. Cross gain modulation (XGM) and cross phase modulation (XPM) in Mach–Zehnder interferometer structure generate CARRY and SUM, respectively, of the half adder. The performance of the device is optimized with respect to input pump powers and effect of amplified spontaneous emission (ASE) noise is also investigated. We have found extinction ratio (ER) as high as 16.48 dB for SUM and 12.95 dB for CARRY which ensures efficient performance of the proposed half adder. The quality factor Q is also high (24.58 dB for SUM and 18.47 dB for CARRY). These confirm clear transmissions of the bits with low bit error rate (BER).

In this paper, recent advancements in radio over plastic optical fibers are reviewed. Plastic fibers are used in short-range, high data rate communication systems and are considered to be consumer-friendly as they are simpler to install, easy to maintain and its associated components are inexpensive. A few of the challenges faced in employing plastic fibers are its high attenuation and modal dispersion, which limits the transmission range. However, plastic fibers are considered to be a low-cost alternative to be employed in short-range fiber-to-the-home (FTTH) networks as compared to the commonly known silica optical fiber. Advancement from 4G to 5G has paved a way for plastic fiber, which can be employed for simultaneous multi-format transmissions supporting 5G networks. In this paper, the evolution of multi-format transmission and its challenges are also discussed, along with the applications of plastic fibers in systems employing various techniques. Furthermore, the paper discusses the challenges and future prospects of radio over plastic fibers to guide a way for further research in this domain for improving the quality of transmission and linking it with other cutting-edge technologies such as machine learning and blockchain.

This article has demonstrated the performance parameters optimization of the Giga passive optical networks (PONs) can enhanced with high transmission data rates with various modulation schemes. These modulation schemes are Mach–Zehnder modulator (MZM), electroabsorption modulator (EAM), amplitude modulator (AM), dual drive MZM measured (DDMZMM), electroabsorption modulator measured (EAMM), and LiNb MZM. The network reach can be extended to 30 km with 20 Gb/s. Maxi Q and mini bit error rate can be measured at both PIN and APD receivers. The study has emphasized AM modulation scheme is the best candidate modulation scheme for upgrading the network performance efficiency. LiNb MZM is the worst modulation scheme for the estimation of PONs performance. Optical power signals after fiber optic channel based different modulation schemes are clarified. EAM modulation scheme is the best technique for upgrading optical power signal through the network reach.

Reach enhancement in inter-satellite optical wireless communication systems (IsOWC) is an utmost requirement due to ever-increasing internet usage all over the globe. Optical code division multiplexing is prominently incorporated for security enhancement in IsOWC systems, however, limited in terms of total reach. Therefore, in this work, a 120 Gbps capacity-based hybrid OCDMA and mode division multiplexed (MDM) IsOWC is presented using different optical amplifiers such as semiconductor optical amplifier (SOA), erbium-doped fiber amplifier (EDFA), and Raman fiber amplifier (RFA). Moreover, the combined effects of Laguerre–Gaussian (LG) with EDFA/SOA/RFA and Hermite–Gaussian (HG) modes with EDFA/SOA/RFA amplifiers are investigated. Results revealed that the proposed system can cover 5000 km IsOWC link within acceptable BER limits and EDFA with LG modes is found to be the best technique.

Theoretical analysis of underwater wireless optical communications (UWOC) systems based on a hybrid LD/LED link in sea water was reported in this research. Multiple input-multiple output (MIMO) and single input-single output (SISO) approaches are used to implement the modulation schemes NRZ-OOK, RZ-OOK, 4-QAM, and 64-PPM. As carriers, waves with the wavelengths 715, 650, 532, and 412 nm are employed. The receiver unit includes the photodiodes PIN and APD to recognize the received signal. The findings indicate that the hybrid LD/LED link’s performance using the MIMO technique is superior to SISO in terms of BER, Q factor, and data rate. Additionally, 64-PPM is a reliable modulation technique for achieving a low BER and a high Q factor.

The work clarified directly measured modulated laser with dual drive measured Mach–Zehnder modulators for signal strength in free space optics (FSO) channel. Peak power after free space communication channel at various propagation distances is measured in the optical time domain. As well as the signal level amplitude quality and data error rates after light detector at various propagation distances are also measured in the time bit period. The directly measured modulated laser with dual drive measured Mach–Zehnder modulators for signal strength in FSO communication channels is stimulated with optisystem program version 13. Peak signal power after free space communication channel at various propagation distances is measured in the optical time domain. The optimum peak signal power is achieved at 10 km distance with a value of 4.328 W. The signal level amplitude quality and data error rates after light detector at various propagation distances are also measured in the time bit period. The optimum Q level and BER level are clarified at 10 km distance with the values of 23.1164 for signal quality and 1.439 × 10 −118 for minimum data error rates.

This study has clarified the optical fiber signal strength based on Raman fiber optic amplifiers schemes in dense wavelength multiplexed communication systems. The signal power with, without Amplification in various pumping configurations scheme is studied with propagation distance variations. The bidirectional pumping power configuration based various pump power is analyzed with propagation distance variations. Amplified forward signal power for various fiber types is investigated with propagation distance variations. These fibers are used such as single mode (SM)-28 fiber, non-zero dispersion shifted fiber (NZDSF), truewave reach fiber for the efficient employment in fiber systems. Amplified bidirectional signal power for various both pump power and fiber types are clarified with propagation distance variations. The pumping power configurations scheme variations are demonstrated with propagation distance variations. Forward/backward pumping power configuration direction variations are investigated and clarified with propagation distance variations for various pumping power values.

A novel high birefringence low loss photonic crystal fiber (PCF) based on terahertz (THz) band is proposed in this paper. By constructing ring cores in core air holes and innermost cladding air holes, the characteristics of the PCF were studied in the band of 0.6–1.2 THz. The simulation results show that the birefringence characteristic of the fiber can reach 0.0514 at 0.6 THz under the optimal parameters. When working at an operating frequency of 1 THz, not only the birefringence characteristic is maintained at 0.044, but also the confinement loss is as low as about 10 −6  dB/m, the dispersion of 0.272 ps/THz/cm and 0.49 ps/THz/cm, the effective mode field area reaches 0.981 μm 2 and 0.745 μm 2 , and the single-mode operating characteristics can be maintained in the entire studied band.

Free space optics (FSO) is considered among the emerging technological innovations which are currently being utilized to supersede radio frequency (RF) communication because of its benefits over it, like, low cost, high speed, optimized bandwidth, reduced error and effective communication. In this regard, a brief and comprehensive survey on the FSO system is proposed in this paper under the impact of weather conditions. Furthermore, extending the review, the working, classification and challenges faced in FSO communication systems have also been explored. As the main objective of this review is to analyze and study the performance of FSO systems under varying environmental and turbulent conditions, therefore, in general, categorized the literature survey into two sections general FSO techniques and optimization-based FSO techniques including key findings, future scope as well as comparison tables for understanding the FSO systems more efficiently.

This study has outlined simulative study on integrated optical multimode waveguides with guided beams based on the system standardization of elements. Deflection of a cantilever are clarified with a point force at the free end, due to the distributed weight at the beam, with a mass at the free end, and at the free end under acceleration. The bending of a double clamped beam under its distributed weight, deflection with the central mass double clamped beam under its weight, the buckling of a double clamped beam due to a compressive stress, out of plane deflection (OPD) of a bent beam suspension, OPD of a folded beam suspension, and OPD of a serpentine beam suspension are also clarified and reviewed. Dependence of cross section of beam on torsion constant is outlined. The stiffness ratio of lateral to vertical motion of hammock suspension is also clarified. The design of a crab-leg suspension and the dependence of the stiffness on thigh section of the crab leg flexure and the design of a folded flexure suspension and the dependence of stiffness on ratio of column beam lengths are also reported.

The next-generation light wave communication DWDM networks can accommodate large number of channels to efficiently utilize the bandwidth (BW). However, in the deployment of DWDM system mixing of two or more waves limits the performance due to four wave mixing (FWM) nonlinearity in fiber. This article, presents improved performance analysis of DWDM using a proposed improved duobinary modulation (IDBM), modified duobinary modulation (MDBM) and duobinary modulation (DBM) model for mitigation of FWM nonlinearities has been estimated experimentally through interference of noise on optical signal, FWM efficiency, FWM power etc. In IDBM, a unit delay in addition to time delay parameter is also utilized for generation of electrical duobinary pulses. The parameters of both delay blocks are tuned through particle swarm optimization (PSO) technique to improve the performance. The overall proposed IDBM effectively decreases the FWM. The results obtained for IDBM in terms of Q-factor 8.9, OSNR 18 dB, FWM power −87 dBm and FWM efficiency −70 dB shows substantial improvement with the recommended IDBM technique in comparison to DBM and MDBM schemes.

Input and output optical signal-to-noise ratio in 16-channel WDM network are investigated for predefined input noise level when design is set at minimum attenuation window. By keeping the input OSNR constant, gain and noise figure are computed along with SNR at both transmitting and receiving terminals for two different data rates and also with short-to-long range of trans-receiver distance. Corresponding variations of all the network properties, i.e., maximum Q-factor, eye height and noise figure are measured for estimation of performance degradation. Optimization in terms of both bit rate and channel distance is required, as evident from simulation result, for best possible system performance. Setting up of input noise level at 20 dBm indicates the fact of real-time compatibility with optimum value of output OSNR is revealed at a particular distance, which suggests the best result for communication system design.

This study has clarified the simulation of the nonlinear cross phase modulation (CPM) performance signature in optical fiber telecommunication systems. We have been clarified the max Q factor in relation to Cross phase shift modulation for the previous models and proposed model. The optimum optical power varied with spectral time and wavelength variation that is simulated for 90° cross phase shift modulation. Optimum total optical and electrical signal power is demonstrated for 90° Cross phase shift modulation. The max signal quality factor and min BER are assured for various degrees based on cross phase shift modulation. In addition to the optimum signal quality factor is emphasized for 90° Cross phase shift modulation.

The enhancements related to optical devices are highly required for high-speed compact wireless optical transmission systems. This paper focuses on development and analysis of the communication system for inter-aircraft applications. The vertical cavity surface emitting laser (VCSEL) is employed at the transmitter for generating directly modulated non-return to zero (NRZ) signal. Direct detection along with Gaussian low pass filtering is employed in the receiver. The performance of the system is examined as well as compared with and without application of filtering at the receiver. The performance of optical wireless system is analyzed in terms of BER, eye-pattern, sensitivity, SNR, and Q -factor. The data rate is enhanced by 4-fold and transmission distance is improved by 250% in comparison with earlier inter-satellite links.

Free space optical (FSO) communication is a propitious technology and emerged as a quintessential candidate for fifth-generation (5G) networks. Inter-channel crosstalk and high cost in wavelength division multiplexed (WDM) systems are predominant limitations. Therefore, in this work, a 180 Gbps WDM-FSO system is proposed by incorporating three different states of polarizations (SOPs) as SOP 0°, SOP 45°, and SOP 90° for the first time. Moreover, the proposed system is investigated in different geographical regions of India such as hilly, desert, coastal, and plain regions. Moreover, the effects of different SOPs on the system are also evaluated in terms of the Q factor and results revealed that SOP 0° performed best in the desert region.

This paper has outlined the simulation study of different operation mode for bit sequence generators variations effects on the transceiver systems efficiency with Manchester coding/decoding technique. The eye diagram signal analyzer after the light receiver is clarified in different mode operation of bit sequence generators. The different mode operation are namely probability, order, alternate, zeros, and ones modes. As well as the received signal amplitude after low pass Bessel filters is examined in different modes operation-based bit sequence generators. Available transmission data rates for this study are 10 Gb/s. The obtained results assured that the system coding performance efficiency is enhanced with alternate mode operation than other proposed modes operation-based bit sequence generators.

This work demonstrates Mach–Zehnder electro-optic modulators chirping management in high speed data communication lightwave systems. The link with applied voltage on the modulators arms is clarified. We have analyzed the chirp in MZ lithium niobate modulators output. The resulted signal passed on the channel that consists of the loop control that we used not to lose too much power because we use an amplifier after a period of fiber reach cable. The resulted signal distance depends on the number of loops multiplied by the fiber reach cable. The next step is to receive the signal by photodetector pin with a responsivity of 1 A/W. The signal after that passed on low pass Gaussian filter with a cut of bandwidth of 0.75 × Bit rate.

This paper deals with the visible-light communication (VLC) network system improvement for high bit rate transmission system. The previous model use the visualizer analyzer for the estimate of bit error rate in which the maxi. Q factor is reached to 2.51. The previous study is used free space channel over along length of 200 km by the optical wireless communication (OWC) channel with available data rates of 4 Gb/s. This presented model has a transmission rate of 10 Gb/s which has a maximum Q factor of 6.34 at the same operating parameters by using CW laser as an optical source and Mach–Zehnder modulator with two cascades optical wireless communication (OWC) channel.

Inter-satellite optical free space communication enabling radio frequencies (RF) is prevalent nowadays due to high speed, prolonged reach, and improved security. Inter-channel interference is the predominant performance deteriorating limitation in wavelength division multiplexed (WDM) based optical communication-based satellite systems (OCSS). Therefore, in this work, a hybrid 16 × 40 Gbps OCSS system with 10 GHz RF signals is presented employing transmitter diversity. Further, three different arrangements of NRZ, AMI, and NRZ-AMI are investigated in terms of log bit error rate (BER) and signal-to-noise ratio (SNR) over a 30,000 km link distance. Results revealed that the transmitter diversity-based NRZ-AMI arrangement offered the best performance followed by AMI non-transmitter diversity system. The proposed system is flexible, economical, and easy to realize.

This paper presented the hybrid Raman and erbium doped fiber amplifiers in amplified wavelength division multiplexed systems. Important role of singly and hybrid light amplifiers are clarified in the presented work. EDFA/RAMAN based average power model based Raman amplifiers are used for strength the signal power levels. CW laser with return to zero code are employed in amplified multiplexed systems. The optimum EDFA optical amplifiers length is used to strength the signal through the optical fiber channel. The max. signal quality and min. error rates are obtained with the presented model. By the assistance of multi pumped lasers for the flat gain in the hybrid EDFA/Raman light amplifiers.

This paper is successfully demonstrated simulative comparison and investigation of 32 channels with 0.8 nm frequency spacing bidirectional wavelength division multiplexing passive optical network (WDM-PON) having 640 and 320 GB/s data rate in downstream and upstream transmission by using CRZ-DPSK/NRZ modulation formats respectively. The maximum reach of the system has been configured to 100 km by employing different post-dispersion compensation techniques such as EDC, DCF, OPC, and FBG in uplink and downlink transmission for compensate the effect of chromatic dispersion in propagating channel. An EDFA optical amplifier is placed after DCF for boosting the amplitude of weak signals downstream. Apart from this, the RSOA amplifier is installed at the ONT end for reflecting and re-modulates the same wavelengths to the CO terminal without using any external optical light source. The performance comparison of distinct compensation schemes are evaluated in terms of BER, Q factor, and Eye diagrams. It has been observed that the FBG and DCF are more robust compensation techniques as compared to EDC and OPC in the bidirectional WDM-PON. The maximum satisfying value of BER has been observed in downlink and uplink transmissions are 10 −26 and 10 −13 for FBG and DCF respectively.

Nowadays, the optical fiber communication system has great importance in the communication area. Although the optical fiber communication system has many favorable circumstances, the dispersion was considered one of the main problems. In this paper, the comparison between the design and simulation of different dispersion compensation schemes was displayed. There are different kinds of optical fiber dispersion compensation systems such as fiber Bragg grating (FBG) and dispersion compensation fiber (DCF) are extensively used for optical communication systems. They are usually considered imperative techniques to compensate for the dispersion. The simulation results have been analyzed depending on various parameters by utilizing advanced Opti-System software. The best performance of the system is when the bit error rate (BER) reaches to 1.7 × 10 −12 at 1550 nm wavelength and the Q-factor is 6.9 at the 0.000195 eye opening. The modal was simulated using the appropriate parameters which include CW laser wavelength, fiber length (km), and attenuation coefficient (dB/km) at the transmitter side. Three various parameters were tested such as BER, Q factor, and eye-opening.

The large number of active users that optical code-division multiple access (OCDMA) offers makes it an attractive technology choice. OCDMA loses its noise immunity due to non-ideal correlation since the maximum auto-correlation and minimum cross-correlation detection technique is required in OCDMA systems. There are several detection techniques like complementary detection, direct detection, etc. This paper presents a new detection technique that is particularly suited for SAC-OCDAM systems with FCZ codes. The simulation results showed that by overcoming the effects of the MAI, significant performance improvements can be achieved.

The fifth generation is the most recent generation of communication needed for high data rates. High spectrum availability, low jitter, high reliability, minimal latency, and increased capacity are just a few benefits of 5th generation. Optical fiber supports the 5G network’s backhaul to meet the enhanced capacity and big data rate requirements. When the fiber is used as a propagation medium, a significant number of nonlinearities manifest. These nonlinearity effects in optical fiber communication are among the most detrimental to modern communication systems because it results in various modulator distortions like phase, harmonic, and intermodulation, distortion, adjoining channel noise, and many more undesirable consequences. The primary fiber nonlinear effects in the radio over fiber communication systems are the Kerr nonlinearity and scattering effects, which are caused by alterations in refractive index as a result of the signal. To overcome these limits, several strategies have been put forth. In particular, the nonlinearity during signal modulation, transmission, and detection has attracted a lot of study attention due to the complex physical layer restrictions in RoF systems. One such fascinating potential is machine learning (ML) methods. In this article, we look at recent advances in ML methods for RoF systems, notably those that use ML models to reduce various types of impairments and improve system performance.

Present article suggested and proposed a new design of 4-bit optical sequence detector using an electro-optic effect by utilizing Lithium niobate (LiNbO 3 ) based Mach–Zehnder interferometer, because of its consistency about production and stability. Suggested sequential detector is designed by OptiBPM (optical beam propagation method) software. This structure uses EO effect to alter the light upon lithium niobate optical waveguide via cross-state to bar-state and replica. Sequence detector is a sequential state machine, that extract an input string of bits and, when the targeted bit has been detected, then it gives an output as 1. In this paper the authors have focused on all-optical 4-bit sequential detector to produce the outcome as 1 when the bit sequence finds as 1101 within the given data. This all-optical device can be utilized in several optical switching and networking operations. The suggested design is replicated with MATLAB along with mathematical descriptions too and has been verified.

In this paper, an efficient cognitive algorithm is proposed to support multiple users, more number of services, and devices under any channel conditions. However, the factors like attenuation, signal penetration loss, received power, fading effects, coverage area, bandwidth, and link quality still remains a significant challenge in the real-world applications. A hybrid FSO/RoF with a cognitive algorithm is proposed to overcome the limitations of existing methods. The proposed algorithm assesses the channel conditions based on various parameters and selects the optimum one for transmission. The simulation results confirm that the proposed method can be reliable under any channel conditions and its performance is compared with the existing methods.

To fulfill the requirement of high data rate with variable quality of service, optical wireless communication is a better option in comparison to existing RF system and is a favorable technological candidate for future optical communication. In wireless optical communication, information is transmitted by propagation of optical wave through the atmosphere. The detrimental effects of channel parameters can acutely limit the utility of an optical wireless communication system. The paper first reviews different channel models in the context to outdoor wireless communication. Different impairments that affect the performance of outdoor optical communication systems and different techniques to mitigate these impairments are then investigated. The upper layer protocols for free space optical communication are also discussed.

This survey presents on the implementations of Quantum Noise Stream Cipher or Quantum Steam Cipher with various modulation formats – like QAM, PSK. FSK, etc., in optical fiber communication systems – along with other pertinent implementation details. Quantum Stream Cipher can be provably secure in information theoretical terms, and it achieves improved security due its inherent (noisy) randomness. This paper presents also a brief review on its claimed improved security, along with the open issues.

Optical fiber transmission capacity is a solution that can fulfill the community’s bandwidth demands, which are on the rise owing to the extensive use of the Internet and cellular communications in contemporary society. It has been observed that fiber optic transmission is influenced due to attenuation. The present research is considering various factors that are responsible for attenuation. In present work 1310 nm and 1550 nm fibers are used for simulation. Simulation has been performed in MATLAB environment using signal distortion, multipath distortion, and attenuation in fiber optics according to increasing distance. Simulation is also considering attenuation in fiber optics with respect to joints for wavelength.

Future high-capacity data links are best suited for free space optical (FSO) communications since they have a larger bandwidth and secure transmission compared to RF links. FSO has several uses including indoor and outdoor settings. The impacts of weather are extensive, with fog being the main mitigating factor reducing link availability. The solution to the problem is to employ a hybrid network with RF/FSO and backup link. Different liquid water densities were used to analyze the performance of the hybrid RF/FSO system in foggy weather. In terms of BER, Q factor, and data rate, a comparison between RF and FSO lines is made. The findings demonstrated that in lower-medium of liquids with water density, the influence of fog weather on RF link is minimal. Under the same situations, an FSO link is useful as a backup link in higher liquid water density concentrations.

In this work, a machine learning approach known as Convolutional Neural Network (CNN) has been proposed for classifying several weights applied on a plastic optical fiber (POF) based on specklegram (speckle pattern) images. We have optimized the CNN model using various inbuilt Keras optimizers namely Adam, Adamax, Nadam, and RMSprop in the python programming language. The best classification accuracy is shown by the RMSprop optimizer with 76.1%. Further, we have achieved improvement in accuracy by employing a transfer learning approach on pre-trained models namely VGG-16 and VGG-19. The classification accuracies of 84.2% and 84.5% are obtained for VGG-16 and VGG-19, respectively. It implies that there is an increase in classification accuracy of around ∼8% after implementing transfer learning. In order to assess the efficacy of the transfer-learned models, we have investigated the surrounding external vibrations applied to a section of the POF at three different frequencies, namely, 10 Hz, 5 kHz, and 50 kHz. We found that the optimal classification accuracy (>70%) is obtained till 5 kHz, beyond which the value decreases drastically. This methodology can lead to the development of real-time, smart sensors for weight detection.

In the application of mobile multimedia and wireless communication system needs an enormous amount of data. Due to the usage of a huge data rate, a superior amount of energy is offered to BER, which effectively enhances the entire energy consumption rate in the system, and also, the generation of CO2 emission leads to global warming. Hence, professionals searched for energy-efficient approaches for attaining enhanced data rates in wireless communication systems. Then, professionals observed the energy efficacy as well as QoS as an essential factor in developing and validating the mobile multimedia communication system that has created superior interest in recent days. In this paper, energy-efficient models are suggested for MIMO-OFDM mobile multimedia communication systems with statistical QoS constraints. Hence, this research suggests a new MTGSO for energy optimization in the MIMO-OFDM mobile multimedia communication system to improve spectral efficiency and system capacity. Thus, the empirical result of the designed method attains better performance regarding average power constraints, achieving 29.8 %, 21.3 %, 123.8 %, and 4.2 % enhanced than SSO, FOA, GSO, and TOA. This energy-efficient hybrid algorithm for MIMO-OFDM proves its efficiency in terms of various performance measures and statistical measures.

This paper is demonstrating the simulative comparisons and investigation of free-space optical fiber optic (FSO/FO) hybrid link under the effects of clear sky, haze and light rain weather conditions by using phase shift keying (PSK) modulation format with a data rate 40 GB/s at 1550 nm wavelength. An optical amplifier with 40 dB gain is placed before the FSO transmitter to boost the amplitude of a weak signal. A combination of multiple FSO transmitters, erbium-doped fiber (EDF) 3 m and bidirectional dispersion compensating fiber (DCF) 3.2 km are employed to overcome the effect of attenuation in the propagating channel. The performance of the system is evaluated in terms of BER, SNR, Q factor and eye diagrams. It has been observed that the performance of dual-channel hybrid FSO/FO is very robust as compared to conventional FSO/FO systems. While the communication distance with the hybrid link is escalated up to 54 km, 11 km and 5.5 km in a clear sky, haze and light rain climate conditions correspondingly. The satisfying values of BER have been observed as 10 −14 , 10 −11 , and 10 −13 for clear, haze and light rain weather conditions, respectively.

In the past decade optical network is growing very rapidly due to the low noise, less bit error rate as well as bandwidth utilization of the network. In this paper explored the bandwidth utilization with the improved gain with less noise and low bit error rate. Previously worked had been done on this area up to the 2nd stage of the optical networks. Previous worked explain the utilization of the bandwidth also explore the allocation of bandwidth in between the two different networks. They also find out the different optimized parameters like bit error rate, delay, gain, and low noise using different methods. But this paper explored up to the fifth stage of the optical network with the optimum parameters has been found out after the simulation. It also explains the bandwidth reuse to the next level of the optical network without any delay provided in between the two consecutive stages. In this explored the future prospective of the next generation optical network and also explain the different module of the stages.

Broadband passive optical networks is an established architecture for the high-speed data transfer. For effective fault diagnosis and self-configuration in these networks, analysis of network-generated data is essentially required. In this era, machine learning-based data analytics approaches could play a vital role in analyzing the performance of the networks. In this paper, a machine learning approach has been proposed for predicting the performance of broadband passive optical networks. For this task, a dataset consisting of fiber length, transmission power, number of power splitters, line width, and extinction ratio parameters has been generated to make an estimate of the Q factor for a given optical network. Out of these network parameters, fiber length, transmission power, and several power splitters are selected through the relief attribute evaluation technique. The selected parameters are fed into a regression-based model tree classification algorithm for estimating different levels of Q factor. This work also takes into account logistic regression, decision tree, decision table, PART, and random forest algorithms for the desired task. The analysis of simulation results proves that the regression-based model tree classification algorithm provides an effective estimate of Q factor in terms of accuracy of 93.23% and 95.74% for 7-class and 3-class problems. Thus, this algorithm appears to be a suitable choice to predict the performance of broadband passive optical networks accurately.

An optical pseudo noise sequence generator based on Mach–Zehnder interferometer (MZI) is proposed. The device consists of MZI and a feedback line. Operability of the proposed device is simulated for continuous wave signals of 1.5 micrometer wavelength. The simulated results shows that all possible sequences of four bit pseudo noise sequence can be generated using proper arrangement of the MZI structures. The operation is numerically analysed and simulated results are discussed. Moreover, various parameters affecting performance of the device are also discussed. The proposed sequence generator can be utilized for different applications in optical wireless communication technology.

This paper successfully demonstrated simulated analysis and investigation of 100 multichannel DWDM-based FSO system having each channel data rate 10 GB/s separated by 100 GHz frequency spacing under adverse weather conditions such as haze, heavy rain and heavy dust fog. Apart from this, a comparison of two modulation formats RZ and NRZ has been performed to optimize the system performance under different climate conditions at diverse visibility ranges. The performances of the proposed work have been compared in terms of BER, Q-Factor, SNR, eye diagrams and received signal power on 193.1 THz. It has been observed that NRZ modulated system showed robust performance as compared to the RZ modulated system for transmitting 1 TB/s data rate over free space with acceptable values of BER ≥ e−22 & Q-Factor ≤ 9.6 dB.

Hybrid wavelength division multiplexing (WDM) and polarization division multiplexing (PDM) technology is a promising candidate for high capacity and extended reach in visible light communication (VLC) systems. However, multilevel modulations and direct modulation are suffered from two predominant limitations in VLC such as high complexity and frequency chirping respectively. Therefore, in this work, a high-capacity VLC system is presented by employing a hybrid WDM-PDM and compressed spectrum return to zero (CSRZ) advanced modulation format. Moreover, direct modulation is replaced with external modulation employing Mach-Zehndar modulators and red/green/blue (RGB) laser diodes (LDs). A detailed comparison of non-return to zero (NRZ) and CSRZ is performed at varied VLC lengths in terms of bit error rate (BER) and Q factor. Results revealed that CSRZ is far better than NRZ and external modulation offered an edge over direct modulation. The maximum VLC distance achieved using CSRZ is 229 cm within acceptable BER limits (10 −3 ) without forward error correction (FEC).

This study has clarified the performance evaluation simulation of the optical splitters integrated with unidirectional fiber elements. The simulative performance evaluation of electrostatic, thermal, and piezoelectric actuation based micro electro mechanical systems. The force against the displacement based electrostatic and elastic forces for parallel plate actuator is simulated by MEMSover simulation software. The voltage with angular displacement for a torsion bar actuator is clarified. Besides the lateral displacement against voltage for a comb drive actuator is reported. The dependence of the film thickness on the deflection of a bimetallic cantilever, the dependence of passive beam length on deflection of a bimorph actuator and the transient response of a bent beam actuator are demonstrated. Moreover the piezoelectric actuator force against applied voltage and the piezoelectric actuator displacement against applied voltage variations are reported.

Orthogonal frequency division multiplexing (OFDM) is advantageous in terms of the spectral efficiency it offers. However, in OFDM, the bandwidth-efficient multicarrier modulation (MM) is limited by the peak-to-average power (PAPR) problem. Iterative clipping and filtering (ICF) method has been used in this work to address such issue. The ICF is regarded as a practical scheme that has become widely accepted and used due to the fact that it is characterized by low computational complexity. This method is also easily implemented, characterized by non-expansion of bandwidth, and it does not require the support to the receiver side during implementation. Nevertheless, the significant of this work is on further improvement where the method involves the iterative clipping of the same signals with a fixed clipping threshold (CT) in every clipping operation. Particle swarm optimization based ICF-OFDM, which is proposed in this research work, literally finds the most suitable clipping ratio, that eventually solves the problem of output power instability. Subsequently, the proposed method is implemented with asymmetrical clipped optical OFDM (ACO-OFDM) to validate the proposed method through the use of Matlab simulation. The PAPR reduction of the proposed method is then compared with the PAPR of the Hartley transform (DHT)-based ACO-OFDM and the traditional ACO-OFDM and DCO-OFDM. The best BER performance has been investigated via two modulation index. Results indicate that our method outperforms the counterparts in term of PAPR reduction and BER performance.

This study outlines the performance based ternary and quaternary III–V compounds in optical communication system. We have employed aluminum dopant ratio to check the effects in the spectral and thermal performance characteristics of various structures of optical diode sources based ternary and quaternary III–V compounds. The laser diode threshold current, reflection loss, corner wavelength, and optical gain are tested under various dopant aluminum ratios. The laser diode rise time and data flow rate are examined under thermal effects and various dopant levels. The laser diode corner wavelength and reflection loss can be enhanced by the increase of aluminum dopant ratio. The basic Al x In 1− x Sb laser diode structure is the best candidate according to its high flow data rates in compared to other laser structures under the same thermal effects.

Terrestrial free-space optical (FSO) links are based on the fundamental idea of a light beam transporting information, enabling extremely high data rates. Fog still presents a significant obstacle to enhancing the availability and dependability of terrestrial FSO lines because the fog particles scatter the light as it travels and only significantly attenuate the signal. Using a hybrid network with an FSO link and a backup link will solve the problem. GHz offers outstanding performance in this frequency band. In this research, the attenuation caused by fog is predicted using an empirical model based on measurements of visibility and their impacts on FSO/RF links. Multiple functioning FSO and RF links operating at 1 GHz, 10 GHz, and 25 GHz, as well as visibility, were simultaneously monitored for changes in signal intensity. The bit error rate (BER) for the optical modulation formats NRZ-OOK, L-PPM, and RZ-OOK is investigated under various fog scenarios. According to the results of the simulation, RF link performance at 25 GHz is better suited for hybrid system fog weather circumstances. On the other hand, we discuss the appropriateness of fog models within these various modulation formats.

This article has analyzed the splicing and coupling influence of cabling to fibers test links measurements. The simulative study for different free/forced vibration mechanics in MEMS is performed. Relative amplitude frequency plot for a cantilever beam, a double clamped beam (DCB), a cantilever beam with end mass, normal vibration of a clamped beam mass, a double clamped beam with axial force, normal vibration of a clamped beam mass are demonstrated by using MEMSolver simulation version 3.3. The frequency shift for DCB with axial force is clarified. The lowest modal frequencies of a square and round diaphragm are also reported. The lowest modal frequency of a bent beam suspension is simulated also. The dependence of mid-section of the folded beam on the resonance frequency and on the short leg of the serpentine beam are clarified. The displacement plot for a structure under free vibration with damping, the displacement plot for vibration under a step force with damping, amplitude frequency plot for vibration under harmonic force with damping and amplitude frequency plot for the vibration driven by the base excitation are also outlined in this work.

This work has clarified the noise multiplication and bandwidth of photodetectors employed with Taylor dispersion in micro optical fiber channel system. The simulation performance evaluation of slide and squeeze film damping and fluidics mechanics. The damping ratio versus gap distance for a cantilever beam and a mass suspended from beams are determined. The damping ratio with gap size for a suspended mass with and without holes is reported. The damping ratio variations with the gap distance variations for a mass suspended from beams is clarified. The velocity field for fluid flow in a circular channel, a square channel, a rectangular channel, a parabolic channel and a triangular channel is estimated. Besides the velocity field for the fluid flow in a channel with and without slip is outlined. The spreading of a diffusion front in one dimension in a resting fluid and the dispersion coefficient in a square channel [Taylor dispersion in micro fluidic channels] are clarified. The 2D diffusion profile of a solute in a T mixer and normalized concentration versus the channel width for the solute at the outlet of H filter are determined.

This study aims to design a thulium-doped Ta 2 O 5 amplifier for short wavelength amplification at 1.7 µm waveband. The waveguide width of the proposed design is theoretically optimized to ensure the condition of single mode guidance and the appropriate width must be less than 3.2 µm. Finite element method based edge element is applied to compute the optical field distribution of the fundamental mode across the waveguide length and to find the values of the overlapping factor and the effective mode field area of the proposed waveguide. The numerical results display that 0.83 and 6.8 µm 2 are the computed values of the overlapping factor and the effective mode field area, respectively at 1.72 µm wavelength. The amplification performance of a Tm:Ta 2 O 5 amplifier is presented based on the rate equations and the power distribution equations. The effects of the waveguide length and the pump power are investigated on the signal amplification at 1.72 µm wavelength. The simulation results reveal that about 25 dB small signal gain and 8.7 dB noise figure could be achieved at 1.72 µm wavelength when pumped with only 100 mW pump power at 1630 nm wavelength. As a result, it is possible to achieve an efficient laser and amplifier source at the 1.7 µm waveband based on a Tm:Ta 2 O 5 waveguide.

This study has clarified various micro electro mechanical system (MEMS) processes performance evaluation based on MEMSolver simulation software. The spin time against final resist thickness for the spin coating of a thin film of photo resist and the oxidation time versus oxide thickness for silicone dioxide growth for <100> silicon in wet oxide are clarified. The diffusion profile for Boron after predeposition and drive in of dopants in silicon and the thickness of silicon dioxide mask for Boron diffusion are demonstrated. The dopant distribution resulting from ion implantation and drive in and the percentage of dose penetrating photo resist mask versus thickness of the mask are reported. The film stress versus the film thickness from wafer bow measurements, aluminum deposition rate against temperature using the electronic beam evaporator and the deposition rate of polysilicon versus silane partial pressure are reported. The etch rate of the thermal oxide against percentage concentration of KOH, the etch rate against the etchant temperature for silicon nitride in hot phosphoric acid, and the etch rate against the etchant temperature for the thermal oxide using buffered hydrofluoric acid (BOE) are outlined.

This paper reported the numerical estimation of co-directional waveguide grating coupler performance transmission characteristics. These dopant materials that are namely phosphorus dopant silica, fluorine dopant silica and boron dopant silica. Transmittivity/reflectivity and three dimension (3D) transmission mesh cross-section of pure silica waveguide grating coupler are outlined with grating dimensions. Coupling efficiency variations is clarified against the grating wavelength and the fill factor variations. Transmission and reflection dispersion of pure silica waveguide grating coupler is reported with grating dimensions. Transmission and reflection delay and dispersion spectrum of various materials-dopant based silica waveguide grating coupler are reported with grating wavelength. The output pulse intensity of pure silica waveguide grating coupler is demonstrated against the time span variations at the link length of 100 km.

This study reported the performance evaluation of various distributors and exchange elements configurations in the optical fiber communication system. The study of different diaphragm structures mechanics under different pressure levels effects. The stress along the x axis of a square diaphragm and the deflection of a square diaphragm under pressure are reported. The radial and tangential stress of a round diaphragm and the deflection of a round diaphragm under pressure are outlined. 3D for the bossed diaphragm deflection against diaphragm position is clarified. The stress distribution across the shorter side of a rectangular diaphragm and 3D for the rectangular diaphragm deflection against diaphragm position under pressure are demonstrated. The radial stress is larger than the tangential stress through the diaphragm radial position from 50 μm to 250 μm for a square diaphragm under pressure. The radial stress is larger than the tangential stress for the bossed diaphragm position varies from 125 μm to 250 μm. All the obtained results are demonstrated through the use of the MEMSolver simulation program software version 3.3.

This study reported the performance evaluation and simulation of passive optical networks for high transmission rates up to 10 Gb/s for possible distance up to 50 km. Laser rate equations, directly modulated laser measured and vertical cavity surface emitting laser (VCSEL) are employed for the measurement of the network performance. Different bit sequences are suggested to show the network performance parameters with various proposed optical sources. Optical and electrical powers are measured for 50 km network reach. In addition to max. Q factor is also measured for various optical sources and bits sequence variations. Laser rate equations are employed in this network to upgrade the Q factor criteria for maximum network reach of 100 km in the downstream direction.

This paper has clarified the gallium aluminum arsenide and plastic modulators and its element circuit modeling design considerations for high signal processing distance links communications. Modulator circuit model design considerations and equations analysis are taken into account. Modulator source resistance, modulator inductance, and modulator capacitance based electro-optic modulator (EOM) is studied and analyzed against temperature variations. In addition to the switching voltage for EOM is analyzed at both 1300 nm and 1550 nm wavelength versus temperature variations. The operation efficiency and maximum modulation resonance frequency are studied for previous and proposed EOM versus modulator length variations. The lower modulator resistance, modulator capacitance, and modulator inductance can be achieved with the proposed EOM. As well as the proposed EOM has outlined the optimum operational efficiency and maximum resonance modulation frequency compared to the previous EOM.

The paper simulates the efficient employment of light sources integrated with both light detectors and free space communication channel under ambient condition effects. The modified duobinary non return to zero line coding system based optical wireless communication channel under light or dense fog level effects. Max. Q factor against OWC reach is simulated at light and dense fog level for the suggested with the previous model. The study emphasis that the OWC length has been reached to 65 km at light fog level and the OWC length has been reached to 5 km at dense Fog level with acceptable signal power. The total light power and total electrical power are illustrated at light and dense fog levels. Max. Q factor and min. BER after receiver based OWC are clarified at light and dense fog levels.

This paper has demonstrated the simulative study of vertical cavity with distributed feedback light sources coupling to the fiber systems. The simulative study of piezoresistive, capacitive and piezoelectric sensing for micro electro mechanical system has been clarified. The span against the diaphragm thickness for the square diaphragm, round diaphragm, a round bossed diaphragm and rectangular diaphragm is clarified. Acceleration against displacement for a capacitive accelerometer for step signal based on signal sided and double sided is reported. Besides, acceleration against max pulse time for a capacitive accelerometer is outlined. The frequency response plot for a piezoelectric accelerometer under longitudinal load and for thin film based piezoelectric accelerometer is demonstrated based on MEMSolver simulation software version 3.3.

Optical encryption techniques in over the last 10 years have become more important in the area of optical information processing. Several applications, including online payments, medical or biometric image storage or transmission, private military applications, police identification techniques, online banking platforms, governmental services, identity (ID) cards, etc., are only a few examples. Require special and reliable security in the transmission and storage of images. Since digital picture information may be readily accessed by hackers via transmission over the Internet or other communication channels, the issue of photos with unlawful usage is becoming more and more severe. A more effective and secure means of communicating images may be offered via optical encryption. The encryption mechanism and keys are needed at the receiver side in order to decrypt the original optical data. Picture security becomes a highly important subject in communication science as a result of network growth and rising need for image transmission. There are several security issues with picture data, including forgery detection and illegal access. The most straightforward method of picture protection is to encrypt it as text. The traditional text encryption algorithms are inappropriate for picture encryption because of the high correlation present in image data. Over the last two decades, a number of optical approaches have been proposed for photo encryption, with the specific advantage of processing two-dimensional (2D) image data in parallel conduction mode. Therefore, we are doing an extensive investigation on optical image encryption in this work.

In this paper, we propose a dual-hop parallel relayed mixed free space optical-underwater optical communication (FSO-UWOC) system model to setup a high-speed communication link connecting a distant sender located at the lighthouse tower and the receiver inside the deep ocean to transmit and receive the data for the applications such as deep sea exploration, marine life study etc. The proposed model is the setup of multiple parallel cooperative dual hop communication link for the betterment of the overall system performance under the worst case scenarios. The receiver examines the end-to-end signal to noise ratio and a relay is selected which has the maximum SNR. The selected relay then decodes the incoming optical signal through FSO link into its corresponding visible light signal and further transmits it to the underwater exploration devices such as underwater drone via VLC link. The FSO link is modelled by the Gamma-Gamma fading distribution and the VLC link is modelled by Exponential Generalized Gamma distribution. The end-to-end SNR of the system is utilized to derived the outage probability of the FSO-UWOC system and the impact of the individual link parameters is studied and presented for the proposed system model.

This study has clarified the bipolar alternate mark inversion encoding scheme for performance signature of optical transceiver systems under thermal effects. The light power through optical fiber channel variations with spectral wavelength at various temperature variations are clarified. The total electrical power through PIN receiver at various temperature variations are demonstrated. The electrical power amplitude, max Q Factor and min BER through PIN receiver at different temperature variations are clarified in details. Electrical and optical signal per noise ratio with laser bias current at various ambient temperatures are demonstrated. The total optical/electrical power and maximum quality signal with laser bias current at various temperature variations.

This study has clarified various RZ Percentage Duty Cycle Coding with NRZ modulation Technique Signature on The Fiber System Performance. The total form lighted/electrical power after linear measured multimode fiber/FSO channel measured based different RZ percentage duty cycle coding with the assistance of NRZ modulation techniques is performed. The electrical/lighted form measured power after APD receiver with linear multimode fiber/FSO channel measured based different RZ percentage base band form duty cycle coding with the assistance of NRZ modulation techniques is demonstrated. The lighted based band form can be used for the modulation of the based band electrical signal form based on the RZ percentage duty cycle coding with the assistance of NRZ for both linear measured multimode fiber and FSO measured channel.

The properties of PCF have been emerged as an interesting field of research for sensing and detection of wavelengths of different refractive indices. These properties indicate that if analyte is used or not in the core of the PCF that does not influence on the sensor sensitivity. By reshaping the airhole’s size, wavelength sensitivity can be improved. The vast detection limit of refractive indices (RI) is taken 1.33–1.41. In addition, high amount of linearity is obtained at the limit of 1.33–1.42. After simulation, it is obtained that this work proposes high sensitivity of 4250 and 6200 nm/RIU for x and y polarization modes. Because of high sensing capability in the range of various frequencies, this PCF can be applicable for other simultaneous wavelength detection. This PCF also offers its eligibility on the field of biomedical technologies.

This study has presented the different suggested compounds based (CAWG) like silicon dioxide (SiO 2 ), lithium niobate (LiNbO 3 ) and gallium aluminum arsenide (Ga (1- x ) Al ( x ) As) taking into consideration their operating wavelength range, their operating temperature range, their physical properties, and also their ability to be used in the manufacture of optical devices. The optimum performance was given in case of using the following materials such as SiO 2 , LiNbO 3 and Ga (1- x ) Al ( x ) As materials, so these materials have been used as a proposed materials based CAWG devices, which have been investigated for high stability and low insertion loss in near infrared wavelength band. The comparison between these proposed materials are clarified through the design parameters of CAWG device such as the order of diffraction ( m ), path length adjacent waveguides difference (Δ L ), focal length ( L f ), free spectral range (FSR), max no. of I/O wavelength channels ( N max ), and arrayed waveguides ( P ) number.

Nowadays ethanol is broadly used chemical item in various industrial purpose. So, detection of this organic chemical has become very important task in industrial basis. In this paper, a hexagonal core PCF has constructed in which silica is used as base material. A finite element method is applied and mesh analysis has been done for investigating boundary conditions of proposed PCF sensor. After simulation, 59.48 % sensitivity and an ignorable loss of confinement which is 8·956020 × 10 −13  cm −1 at 2.5 THz frequency has been gained. Focusing on easy construction of fiber, conventional fabrication procedures are attainable. Having satisfactory waveguiding attributes, the proposed sensor can be applicable effectively for sensing ethanol and also polarization-based applications of terahertz waves.

The optical add drop multiplexers (OADMs) to be modeled and analyzed depends up on the simulation variables are demonstrated. Transmitted power per channel variations are studied against both fiber length and number of transmitted channels at receiver bandwidth of 40 GHz and temperature of 25 °C. Received power from each channel variations are demonstrated against both fiber length and number of transmitted channels at receiver bandwidth of 40 GHz and temperature of 25 °C. The bit error rate variations are clarified against both fiber length and number of transmitted channels at receiver bandwidth of 40 GHz and temperature of 25 °C. The optical link map through fiber cable core is clarified. Total pulse broadening variations are illustrated against both fiber length and number of transmitted channels at receiver bandwidth of 40 GHz and temperature of 25 °C. The lighted signal/noise ratio variations are demonstrated against both receiver bandwidth and number of transmitted channels at transmission distance of 200 km and temperature of 25 °C. Channel capacity variations are also demonstrated against both receiver bandwidth and number of transmitted channels at transmission distance of 200 km and temperature of 25 °C.

This work demonstrates the optical duobinary transmitter based optical quadature phase shift keying line coding phase offset for the prediction of optical fiber wireless channel systems performance efficiency. The max signal light power variations with the spectral wavelength variations for different degree phase offsets based optical quadrature phase shift keying (OQPSK) transmitter are clarified. The max signal light power variations with the time variations for various degrees phase offset based OQPSK transmitter are demonstrated. The total power lighted after OWC channel for various degree phase offset based OQPSK transmitter are indicated. The max electrical power signal amplitude variations with the time variations for various degree phase offset based OQPSK transmitter are observed. Total electrical power signal after optical receiver for various degree phase offset based OQPSK transmitter is clarified. Total optical power variations after OWC channel for various degrees phase offset based OQPSK transmitter is studied.

Fuel quality has a significant impact on the lifespan and smooth operation of petroleum engines. Many dishonest merchants mix lower priced oil/ingredients with petroleum products to increase their profit. To solve this problem, a terahertz waveguide-based fuel adulteration sensor that can detect the presence of kerosene in gasoline is proposed. The design procedure is performed by large elliptical hollow core photonic crystal fiber including rectangular cladding. In our study, the used sensor’s performance is investigated and FEM is also used for performing numerical analysis. Our used sensor achieved a maximum 80.34% sensitivity with a negligible total loss having 3.74 × 10 −2  cm −1 during 2.8 THz optimum operating frequency conditions which are very impressive. Additionally, under ideal circumstances, the used sensor attained a sound birefringence of 0.01 and 0.034 ranging numerical aperture. The proposed sensor’s structure is quite simple which might make the fabrication process easy. Furthermore, because of the higher sensitivity and guiding properties, the sensor will be an important part of real-life applications in the forthcoming years.

This work has been clarified the optical differential phase shift keying transceiver systems performance efficiency at high data rate optical systems in the presence of pr doped amplifiers. The Max optical signal power variations after fiber link versus wavelength variations at various system data rates are demonstrated. The total optical power within optical fiber at data rates from 10 to 100 Gbps are indicated. The Max electrical signal power variations against frequency after receiver variations at various system data rates are clarified. The total electrical power after receiver at various system data rates are demonstrated. The light/electrical power received, OSNR and SNR variations in relation to data rate variations are also studied.

This study has demonstrated the efficient employment of optical DPSK transmitter with linear multimode fibers and FSO channel under various duty cycle coding effects. The light signal power form variations after linear multimode fiber versus spectral wavelength based various RZ-percentage duty cycle coding is clarified. The light signal power form variations after linear multimode fiber versus spectral wavelength based various NRZ duty cycle coding is also clarified. The light power signal form variations after FSO channel versus spectral wavelength based different RZ percentage duty cycle coding is analyzed. Moreover the light power signal form variations after FSO channel versus spectral wavelength based NRZ percentage duty cycle coding is investigated. The light signal power form variations after linear multimode fiber versus spectral wavelength based various RZ percentage duty cycle coding and NRZ modulation code are indicated.