Space phase compensation system in orbital angular momentum optical communication, and method thereof

Abstract

The invention discloses a space phase compensation system in orbital angular momentum optical communication, and a method thereof, and relates to the liquid crystal space spatial modulation technology, and in particular to phase compensation of vortex beams in space optical communication. The system comprises a light source, a modulation OAM, mode multiplexing, a free space, a demodulation OAM andcoherent detection, which communicate with each other in sequence; and any beam phase reflected by a liquid crystal spatial light modulator is compensated on a sending end and a receiving end by using an iterative phase recovery algorithm, thereby improving the imperfect state of the symmetry of the vortex beams caused by atmosphere turbulence, improving the quality of the beams and facilitatingthe subsequent utilization and transmission.Compared with the prior art, the space phase compensation system disclosed by the invention realizes the phase distortion existing in a stepwise correctionspatial optical communication system, (2) improves the quality of the generated vortex beams and the quality of receiving demodulation to a certain extent,comprehensively improves the signal to noiseratio of the whole system and reduces the bit error rate; and the space phase compensation system is simple in structure and is easy to implement.

Description

technical field [0001] The invention relates to liquid crystal spatial light modulation technology, in particular to a spatial phase compensation system and method in orbital angular momentum optical communication, in particular to phase compensation for vortex beams in spatial optical communication. Background technique [0002] Beams with Orbital Angular Momentum (OAM) are called vortex beams, and vortex beams have a phase factor in is the direction angle, and l is the topological charge, that is, the number of times the wavefront rotates in one wavelength. In theory, l can be any integer, that is, it has infinitely many eigenstates. [0003] Since the use of vortex beams with different topological charges to realize mode multiplexing transmission information can greatly expand the system capacity and realize optical transmission with high spectral efficiency, so the preparation, transmission and reception of OAM beams have received extensive attention and research. wi...

AI Technical Summary

Problems solved by technology

Adaptive optics systems are currently the most promising technology for compensating for wavefront distortion during imaging caused by atmospheric turbulence or other factors, and the system must use limited data to analyze and perform wavefront distortion every millisecond. Correction, although it does improve the communication effect, it requires high precision of optical components, complex technology, and high cost, so it is difficult to be widely used in actual communication occasions

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