Model-free wavefront distortion correcting system based on spatial light modulator

Abstract

The invention provides a model-free wavefront distortion correcting system based on a spatial light modulator. The system consist of a polarizing sheet 1, a telescopic system 2, a beam splitter prism 3, a shrinkage device 4, a CCD camera 5, a computer system 6, the spatial light modulator 7, a wavefront controller 8 and a monitoring camera 9. The common CCD camera is adopted to form images; a Strehl ratio of beams is analyzed according to the model-free iteration theory to obtain control signals of optimization parameters required by a wavefront corrector; the performance indexes of the system such as imaging definition, receiving light energy and the like are directly used as objective functions of an optimization algorithm to optimize and acquire the correction effect close to a diffraction limit; and the optimization parameters are calculated in parallel by a computer with a graph processor, the acquired multi-channel control signals are transmitted to the wavefront controller, and then the wavefront controller drives the spatial light modulator to achieve real-time correction of wavefront distortion phase so as to effectively solve the problem of wavefront distortion in atmospheric laser communication.

Description

technical field [0001] The invention relates to a model-free wavefront distortion correction system based on a spatial light modulator. Background technique [0002] With the application of laser in the fields of industry and national defense, the influence of atmosphere on laser transmission has been widely paid attention to. The main effects of the atmosphere on the laser are: atmospheric absorption, atmospheric scattering and atmospheric turbulence effects, among which the atmospheric turbulence effect has the greatest impact on the quality of laser transmission and communication. The main effects of atmospheric turbulence effects are light intensity scintillation, phase fluctuation, angle of arrival fluctuation, beam expansion and drift, etc., which will increase the bit error rate of the atmospheric laser communication system, and in severe cases, the communication will be interrupted. [0003] The core content of traditional adaptive optics is to correct the beam dist...

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Problems solved by technology

[0006] With the expansion of the application field of laser technology, such as free space optical communication, laser ranging, etc., the phase fluctuation phenomenon causes the discontinuity of the beam wavefront, which brings a large error to the wavefront detection, and the phase conjugation based method cannot be realized. Compensation, the compensation effect is greatly limited, resulting in the difficulty of wavefront measurement, resulting in the failure of traditional adaptive optics systems that rely on wavefront measurement, so the application of traditional adaptive optics control technology in these cases appears powerless

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