Sodium guide star laser atmospheric link compensation system

Abstract

The invention relates to the technical field of a self-adaptive optical system, and in particular to a sodium guide star laser atmospheric link compensation system. The system comprises a first laserbeam expanding system, a second laser beam expanding system, a dichroic mirror, a deformation mirror, a beam combining and expanding system, a wavefront detection and control system, a reflecting mirror and a calibration light source. According to the system, another laser different from the sodium laser wave length and the sodium laser combining beam are emitted in common-caliber and are converged on an atmospheric layer of a sodium laser transmission path to generate atmospheric back scattering; the atmospheric turbulence distortion is measured and compensated by using a back-scattering image; when the sodium laser emits, the phase distortion opposite to the atmospheric turbulence is carried and counteracted when the laser passes through the atmospheric turbulence so that the sodium laser has flat wavefront distributions, smaller light spot diameter and higher energy density when reaching the sodium layer for convergence, thereby being beneficial to reducing the measurement error ofthe self-adaptive optical system of the ground-based optical telescope and improving the imaging correction effect.

Description

technical field [0001] The invention relates to the technical field of adaptive optical systems, in particular to a sodium guide star laser atmospheric link compensation system. Background technique [0002] Sodium guide star laser technology refers to the use of a beam of laser whose central frequency can resonate with the transition line of sodium atoms to excite the sodium layer at a height of about 92km from the ground to emit resonant backscattered light, which is used as the guiding light source of the adaptive optics system and has sampling Highly advanced advantages. However, in practical applications, the upward transmission process of the laser beam of the sodium guide star will be disturbed by atmospheric turbulence, the distribution of the laser wavefront will be distorted, the convergence characteristics in the sodium layer will become worse, the star points will diffuse, and the center intensity will decrease, that is, the sodium guide star As the angular widt...

AI Technical Summary

Problems solved by technology

However, in practical applications, the upward transmission process of the laser beam of the sodium guide star will be disturbed by atmospheric turbulence, the distribution of the laser wavefront will be distorted, the convergence characteristics in the sodium layer will become worse, the star points will diffuse, and the center intensity will decrease, that is, the sodium guide star As the angular width increases, the brightness decreases, which in turn causes the main telescope adaptive optics system to increase the measurement wavefront error, reducing the effect of correction and high-resolution imaging

Images