Optical Orbital Angular Momentum Demultiplexing and Channel Equalization by Using Equalizing Dammann Vortex Grating

Abstract

A novel equalizing Dammann vortex grating (EDVG) is proposed as orbital angular momentum (OAM) multiplexer to realize OAM signal demultiplexing and channel equalization. The EDVG is designed by suppressing odd diffraction orders and adjusting the grating structure. The light intensity of diffraction is subsequently distributed evenly in the diffraction orders, and the total diffraction efficiency can be improved from 53.22% to 82%. By using the EDVG, OAM demultiplexing and channel equalization can be realized. Numerical simulation shows that the bit error rate (BER) of each OAM channel can decrease to 10 −4 when the bit SNR is 22 dB, and the intensity is distributed over the necessary order of diffraction evenly.

Two-Dimensional Optical Metasurfaces: From Plasmons to Dielectrics

“…In recent years, the development of light field modulation has been increasing. For example, the generation and application of vortex and vector light have always been hot research [29][30][31][32][33][34]. Plasmons have also proven that they can be applicable to optical modulation [35], just like the generation of ring-shaped beams in carbon disulfide by using a graded-index plasmonic lens [36].…”