Measurement and analysis of wavefront structures of diode lasers
-
Inga-Maria Eichentopf
Inga-Maria Eichentopf has studied physics in Jena and Leipzig where she also received her PhD on the field of plasma surface interaction. Since 2014 she is research associate at the Institute of Natural Sciences at the Hochschule Ruhr West. Currently she is working on the matter of wavefront analytics and intensity simulations of multimode diode lasers.
Hochschule Ruhr West – Institute of Natural Sciences, Duisburgerstr. 100, 45479 Mülheim an der Ruhr, Germany
and
Martin Reufer
Martin Reufer has studied physics at the RWTH Aachen with focus on semiconductor physics and laser technology. During his PhD at the Ludwig-Maximilians University in Munich he did research in the field of organic optoelectronic devices. Before joining the Hochschule Ruhr West as Professor for Applied Physics, he worked as a development engineer with OSRAM OS in Regensburg with focus on high power laser diodes.
Hochschule Ruhr West – Institute of Natural Sciences, Duisburgerstr. 100, 45479 Mülheim an der Ruhr, Germany
Abstract
In order to analyze the beam quality of laser sources wavefront measurements using a Shack–Hartmann sensor became an established way. With the detection of the wavefront deflection a change of the modal composition of the laser beam can be recorded directly. While this method is well known for nearly Gaussian laser beams, the wavefront analysis of broadarea semiconductor lasers is an open field of current research. Detailed analysis of the wavefront gives an additional path to get an insight into the transverse modal composition of semiconductor lasers, which have a dominant impact on the output parameters of the devices. For the presented investigations lasers emitting light in the near infrared (λ = 830/980 nm) based on the material system GaAs are utilized. For this type of laser the number and structure of optical modes is affected by thermal as well as electric effects inside the active medium. It is shown that the detected wavefront can be associated with a composition of Legendre polynomials. Additionally the transformation of these polynomials is examined under changing working conditions of the laser.
Zusammenfassung
Zur Analyse der Strahlqualität von Laserquellen stellt die Vermessung der Wellenfronten unter Verwendung eines Shack–Hartmann-Sensors eine etablierte Methode dar. Durch die Detektion der Wellenfronten kann eine Veränderung der Zusammensetzung der optischen Moden im Laserstrahl direkt festgestellt werden. Während diese Methode für Laserstrahlen mit nahezu gaußförmiger Intensitätsverteilung gut verstanden ist, stellt die Analyse der Wellenfronten von Breitstrahlhalbleiterlasern ein aktuelles Forschungsgebiet dar. Die detaillierte Untersuchung der Phasenverteilung bietet einen erweiterten Zugang zur Zusammensetzung der optischen Moden, welche einen dominanten Einfluss auf die Abstrahlcharakteristik von Halbleiterlasern hat. Für die hier gezeigten Untersuchungen wurden Laser basierend auf dem Materialsystem GaAs verwendet, die Licht im nahen Infrarot (λ = 830/980 nm) emittieren. Für diesen Typ von Lasern wird die Anzahl und Struktur der optischen Moden sowohl durch thermische als auch elektrische Effekte im aktiven Medium bestimmt. Es wird gezeigt, dass die Form der gemessenen Wellenfront durch Legendre-Polynome beschrieben werden kann. Weiterhin wird die Veränderung der Polynome in Abhängigkeit der Arbeitsparameter des Lasers untersucht.
About the authors
Inga-Maria Eichentopf has studied physics in Jena and Leipzig where she also received her PhD on the field of plasma surface interaction. Since 2014 she is research associate at the Institute of Natural Sciences at the Hochschule Ruhr West. Currently she is working on the matter of wavefront analytics and intensity simulations of multimode diode lasers.
Hochschule Ruhr West – Institute of Natural Sciences, Duisburgerstr. 100, 45479 Mülheim an der Ruhr, Germany
Martin Reufer has studied physics at the RWTH Aachen with focus on semiconductor physics and laser technology. During his PhD at the Ludwig-Maximilians University in Munich he did research in the field of organic optoelectronic devices. Before joining the Hochschule Ruhr West as Professor for Applied Physics, he worked as a development engineer with OSRAM OS in Regensburg with focus on high power laser diodes.
Hochschule Ruhr West – Institute of Natural Sciences, Duisburgerstr. 100, 45479 Mülheim an der Ruhr, Germany
Acknowledgement
The authors acknowledge Hochschule Ruhr West (HRW) for financial support through an initial funding program. Additionally we thank Dr. Daniel Asoubar and Dr. Hagen Schweitzer from Light Trans (Jena) for technical support on the intensity simulations.
©2016 Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Frontmatter
- Editorial
- IEEE Workshop on Industrial and Medical Measurement and Sensor Technology – SENSORICA 2016
- Beiträge
- A metamaterial based dual-resonant coil element for combined sodium/hydrogen MRI at 7 Tesla
- Emission spectroscopy based sensor developed for engine testing
- Molecular laser-induced breakdown spectroscopy for elemental analysis
- Quantitative measurement of complex substances dissolved in an ionic liquid using IR spectroscopy and chemometrics
- Methods to determine the scaling factor in X-ray images for exact preoperative planning in hip surgery
- Development of an optical tracking system for a novel flexible and soft manipulator with controllable stiffness for minimal invasive surgery (MIS)
- Telemetric multi-sensor system for medical applications – The approach
- Measurement and analysis of wavefront structures of diode lasers
Articles in the same Issue
- Frontmatter
- Editorial
- IEEE Workshop on Industrial and Medical Measurement and Sensor Technology – SENSORICA 2016
- Beiträge
- A metamaterial based dual-resonant coil element for combined sodium/hydrogen MRI at 7 Tesla
- Emission spectroscopy based sensor developed for engine testing
- Molecular laser-induced breakdown spectroscopy for elemental analysis
- Quantitative measurement of complex substances dissolved in an ionic liquid using IR spectroscopy and chemometrics
- Methods to determine the scaling factor in X-ray images for exact preoperative planning in hip surgery
- Development of an optical tracking system for a novel flexible and soft manipulator with controllable stiffness for minimal invasive surgery (MIS)
- Telemetric multi-sensor system for medical applications – The approach
- Measurement and analysis of wavefront structures of diode lasers
