Space laser beam fiber coupling efficiency optimization method capable of overcoming atmosphere 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 optical fiber coupling efficiency of a space laser beam for overcoming atmospheric turbulence. In particular, a method for simultaneously controlling fast mirrors and phase controllers to achieve high coupling efficiency of optical fibers by using blind optimization technology belongs to the field of free-space laser transmission. Background technique [0002] Space laser beam transmission such as satellite-to-ground laser communication is usually detected by fiber-coupled detectors, and its fiber coupling efficiency directly affects communication efficiency and coding 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, as well as factors such as processing and assembly errors of optical antennas and mechanical vibrations, the wavefront of the laser beam will be distor...

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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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