Volume 9, Issue 4

Driven by greatly increased applications, the optical see-through displays have been developing rapidly in recent decades. As a result, some innovative technologies have emerged toward making the display more compact and lighter with better performance. This paper serves as a systematical review on the advances in developing optical see-through displays, including the physical principles, optical configurations, performance parameters and manufacturing processes. The design principles, current challenges, possible solutions and future potential applications are also discussed in the paper.

Here we define a theoretical basis for the generalization of the beam quality factor M 2 to three-dimensional (3D) space, which we call M 6 formalism. The formalism is established through the use of examples of multifocal and Axicon optical systems to illustrate discrete and continuous axial beam shaping, respectively. For the continuous case, we expand the definition of the Rayleigh range to incorporate a quality factor having both axial and transverse components Madd2$M_{{\rm{add}}}^2$ and M 2 . Using geometrical ray tracing simulations, a proportion factor C is found to empirically describe the axial quality factor Mz2$M_z^2$ of an optical setup including an Axicon and a paraxial focusing lens with a Gaussian single mode input beam. Using our M 6 formalism depth of focus (DOF) ranges are calculated for higher M 2 beams, and are shown to be in good agreement with the simulated DOF range, demonstrating the usefulness of the M 6 formalism for the design of real optical systems.

The presence of native oxide layers on aluminum mirrors can be a nuisance for precision optical design. As the native oxide thickness varies from mirror to mirror, its effect cannot be completely canceled even in the conventional crossed fold mirror geometry. We show how this effect arises and how it can be mitigated, and provide an experimental demonstration in which the residual linear retardance and linear diattenuation are reduced to <0.14° and <0.001, respectively, over the visible and near-infra-red spectral range.

Two optical sensing elements based on the surface plasmon waves at the plasmonic-photonic-crystal/air interface, excited in the Kretschmann configuration, are proposed. The sensing elements are designed to detect air humidity and NO 2 concentration in air. The angular reflectance spectra of the sensing elements are theoretically analyzed as the function of the analyte concentration. The proposed NO 2 -sensing element has no cross-sensitivity to humidity. The two sensing elements are based on the same multilayer metal-dielectric structure with the only exception on different gas-sensitive material layers. When combined, the sensing elements can be used to measure humidity and NO 2 concentration in humid air.

Distribution of the atomic polarization in a Cesium vapor cell, induced by optical pumping, is analytically calculated and discussed when an external magnetic field interacts with the system. Based on the rate equations of the optically pumped atomic system and considering the effect of magnetically induced dichroism on the absorption of polarized propagating light, we have obtained the light intensity and atomic polarization distribution along the propagation direction of the gas cell. It is shown that based on the initial light polarization and the laser detuning, the external magnetic field considerably changes the polarization distribution. The obtained results of the polarization distribution versus applied magnetic field can be used for different investigations, including the study of the atomic magnetometer’s sensitivity.