A Method for Optimizing Coupling Efficiency of Space Laser Beams to Fiber Optics Overcoming Atmospheric Turbulence

Abstract

The invention discloses a space laser beam fiber coupling efficiency optimization method capable of overcoming atmosphere turbulence. The method comprises the following steps that beam drift is inhibited by using a fast steering mirror when various factors resulting in beam wandering and spot energy concentration ratio descending are comprehensively considered; beam wavefront distortion caused by atmosphere turbulence and static system aberration is compensated by a phase controller, and the fiber coupling efficiency as an objective function is optimized by adopting a blind optimization control strategy, so that the fiber coupling efficiency is converged and maintains high level, the adverse coupling efficiency effect caused by atmosphere turbulence and static system aberration is overcome and the fiber coupling efficiency is greatly improved. According to the method, position and wavefront sensors are absent, the fiber coupling efficiency is converged and maintains high level by simultaneously adopting blind optimization control to the fast steering mirror and control voltage of the phase controller. The method is simple in principle and easy to realize, thus the method has a significant application prospect in the field such as satellite-to-ground laser communication, laser radar and satellite-to-ground quantum communication.

Description

Technical field [0001] The invention relates to a method for optimizing the coupling efficiency of a space laser beam fiber to overcome atmospheric turbulence. In particular, it is a method for simultaneously controlling a fast reflector and a phase controller to achieve high coupling efficiency of optical fibers by using blind optimization technology. The invention belongs to the field of free space laser transmission. Background technique [0002] Space laser beam transmission such as satellite-to-ground laser communication usually uses fiber-coupled detectors for detection, and its fiber coupling efficiency directly affects communication efficiency and code rate. Therefore, how to improve the fiber coupling efficiency at the receiving end is one of the key technologies to be solved. However, due to the influence of atmospheric turbulence, the processing and assembly errors of the optical antenna, and mechanical vibration, the wavefront distortion of the laser beam will cause ...

AI Technical Summary

Problems solved by technology

However, this method does not use fast mirrors, which cannot suppress the influence of beam offset; and the optimization object of this system is the energy entering the photodetector after beam splitting, rather than the coupling efficiency based on the energy coupled into the fiber. In addition, from a principle point of view, this method is only an application of an optimized adaptive optics system, and cannot fundamentally solve the problem of coupling efficiency decline

[0004] To sum up, there is still a lack of a method that can maximize the coupling efficiency of space laser beams and is simple in structure and easy to control.

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