Encoding and decoding communications based on perfect vector optical vortex arrays

Abstract

We proposed the perfect vector optical vortex arrays (PVOVAs) for encoding and decoding communications, including the 2×2, 1×4, 4×4, and 2×4 array forms, which were generated with the coaxial superposition of two vector optical vortex arrays with left- and right-handed circular polarization. The polarization order and state of each vector element could be modulated independently by adjusting the corresponding topological charges (TCs) and additional phases, θn. By attaching code information to these vector elements with different states of polarization, the hexadecimal code elements, including 0 to F, were represented. Therefore, PVOVAs consisting of multiple vector elements can transmit encoding information and be decoded as original information in the receiving end. The bighorn sheep grayscale image, with a size of 64×64 pixels, was transmitted using the encoding and decoding communication via PVOVAs, and the received restored image had a reliable accuracy. This study proves PVOVAs have flexible spatial structure and controllable state of polarization, and it expands the application of vector optical fields in optical encoding and decoding communication.

Dynamic control of hybrid grafted perfect vector vortex beams

“…The same intensity profile contains multiple higher-order polarization distributions. The existence of small ring with very weak intensity is due to the parasitic light, which comes from the crosstalk between two rings 34 – 36 . The parasitic light can be minimized by optimizing the axicon period and the size of the metasurface.…”

Unidirectional reflectionless propagation in borophene plasmonic metamaterials

“…The previous works were based on fitting these relative parameters, and there was no analytical analysis of the unidirectional reflectionless phenomenon. Well, Lu et al proposed a feasible method to calculate internal losses [38][39][40]. And the radiative rate is enhanced in a monolayer graphene nanoribbons when the edges are clustered together, as observed experimentally by Semenenko et al [41].…”

Planar crossed-fork gratings with sinusoidal transmittance for eliminating high-order diffraction

“…It can be seen that after the planar beam passes through the PCFGs, the diffracted beam array at the focal plane carries vortex phases of different orders, which is also consistent with Eq. (10). Every phase singularity in the figure corresponds to the center position of the vortex beam array.…”

“…Optical vortex arrays (OVAs), due to their ability to process data in parallel using spatial degrees of freedom, has recently seen notable applications in optical communication, 1 – 4 high-resolution far-field microscopy, 5 orbital angular momentum (OAM) multiplexing, 6 , 7 optical anti-counterfeiting, 8 , 9 and strong data encoding 10 – 14 Thus, considerable effort has been devoted to developing methods for realizing OVAs 15 …”

“…Optical vortex arrays (OVAs), due to their ability to process data in parallel using spatial degrees of freedom, has recently seen notable applications in optical communication, [1][2][3][4] high-resolution far-field microscopy, 5 orbital angular momentum (OAM) multiplexing, 6,7 optical anticounterfeiting, 8,9 and strong data encoding. [10][11][12][13][14] Thus, considerable effort has been devoted to developing methods for realizing OVAs. [15][16][17][18][19][20][21][22][23] Currently, three commonly used methods for generating OVAs are multi-beam interference, [24][25][26] specifically microstructured materials, 27 and customized diffraction gratings.…”