Numerical demonstration of low-reflective wire grid polarizers with a patterned Fe2O3 absorptive layer.

Absorptive polarizers are pivotal components for realizing a low ambient reflection in liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs). Different types of absorptive polarizers have been proposed. Nevertheless, the realization of compact and efficient absorptive polarizers remains challenging. Wire grid polarizers (WGPs) are a promising solution because of their high durability and relatively thin thickness. In this paper, two structures of absorptive-WGPs have been proposed and optimized at the target wavelength of 532 nm: one is based on a patterned F e 2 O 3/A l bi-layer on top of a S i O 2 substrate, and the second one builds on the first one by depositing a S i O 2 layer in the gaps of Al. The optimal solutions exhibit a reflectance less than 5%, a transmittance over 45%, and an extinction ratio over 40 dB. To evaluate the manufacturing feasibility, their sensitivity to the wire's dimensional parameters is investigated. Their great spectral performance and large acceptance angles demonstrate that such polarizers have the potential to significantly promote the development of current display technologies.

Improvement of coupling efficiency in free-space optical communication with a multi-actuator adaptive lens.

In free-space optical communication, the propagation of a laser beam through the atmosphere causes wavefront distortions that decrease the coupling efficiency (CE) from free space to single-mode fiber. This tremendously degrades the performance of the communication channel even in the case of weak turbulence regime. In this Letter, we demonstrate that a multi-actuator adaptive lens working in closed loop with a wavefront sensor can strongly reduce the effect of turbulence while reducing the system complexity with respect to correction systems using deformable mirrors or liquid crystal spatial light modulators. We obtain a three-fold increase in the CE in weak turbulence regime.

Performance evaluation of perfect optical vortices transmission in an underwater optical communication system.

In this paper, we experimentally evaluated the performance of underwater optical communications using 1 Mbit/s on-off keying signals of perfect optical vortices. Perfect optical vortices generated by Fourier transformation of the Bessel-Gaussian beam are propagated through a 2.6 m underwater medium and affected by various water conditions such as stagnant water, water flow, temperature difference, and air bubbles, so beam wander and fluctuation of the signal are studied. Air bubbles have the maximum effect on signal fluctuations and beam wanders. Measurement of the system bit error rate (BER) based on the signal-to-noise ratio (SNR) for these situations matches the results of wandering and fluctuations. The system BER is studied for different values of SNR, and its value is more degraded due to the air bubbles.

Performance evaluation of perfect optical vortices transmission in an underwater optical communication system: publisher's note.

This publisher's note identifies an error in the paper title of Appl. Opt.57, 9148 (2018)APOPAI0003-693510.1364/AO.57.009148.