Spatial-Light-Modulator-Based Multichannel Data Transmission by Vortex Beams of Various Orders

Abstract

We report an atmospheric multichannel data transmission system with channel separation by vortex beams of various orders, including half-integer values. For the demultiplexing of the communication channels, a multichannel diffractive optical element (DOE) is proposed, being matched with the used vortex beams. The considered approach may be realized without digital processing of the output images, but only based on the numbers of informative diffraction orders, similar to sorting. The system is implemented based on two spatial light modulators (SLMs), one of which forms a multiplexed signal on the transmitting side, and the other implements a multichannel DOE for separating the vortex beams on the receiving side. The stability of the communication channel to atmospheric interference and the crosstalk between the channels are investigated.

Recent Advances in Generation and Detection of Orbital Angular Momentum Optical Beams—A Review

“…For example, Figure 15 shows detecting results for the phase 13-channel filter, matched with integer and half-integer OVs [ 193 ]. Note, DOEs can be employed to recognize not only the singular phase state of structured light beams but also for detection polarization state [ 4 , 5 , 6 , 194 ]. However, MSs are more suitable for these purposes [ 195 , 196 , 197 , 198 , 199 , 200 ].…”

“… Detecting OVs: ( a ) phase of a 13-channel filter; ( b ) intensity pattern (negative) in the focal plane and correspondence of diffraction orders to OV values; and ( c ) results of detecting of different OVs in the beam with co-axial superposition exp(− i 2φ) + exp(− i φ) (total OAM μ = −0.5) [ 194 ]. …”

Free-Space Transmission and Detection of Variously Polarized Near-IR Beams Using Standard Communication Systems with Embedded Singular Phase Structures

“…Multichannel data transmission in free space can be achieved by means of laser beams with different properties [ 1 , 2 ]. The most common approach is the use of vortex beams of various orders [ 3 , 4 , 5 , 6 , 7 ], as well as cylindrical vector beams [ 8 , 9 ]. To multiplex information transmission channels, it is also possible to exploit both phase and polarization degrees of freedom [ 10 , 11 , 12 ].…”

Controlling Dispersion Characteristic of Focused Vortex Beam Generation

“…Since it was first discovered by Allen et al in 1992 [5], vortex beam has shown great application potential in optical tweezers technology [6], super-resolution imaging [7], space optical communication [8], quantum entanglement [9], and other fields. At present, there are many methods available for generating vortex beams, such as helical phase plates [10], mode conversion [11], and spatial light modulators [12]. However, these conventional methods require the construction of relatively bulky optical systems.…”