准直光束的温度场影响分析

Analyses of effect of temperature field on the alignment beams

在激光准直技术中,产生误差的主要因素有激光光束漂移、光线弯曲和随机抖动。对大尺寸激光准直测量,后两项误差的影响尤其突出。近年来产生了自适应准直的思想,即控制反射镜等元件的运动,使光束通过两个基准孔径,以期得到光线基准。这种方法是建立在“光直线传播”的基础上,然而这个条件在真实大气中是不满足的。本文根据对长距离激光准直光束特性的分析,提出了多点监测、综合补偿的准直方法,这种方法的特点是建立一个任意曲线的光束轨迹模型。由于这个模型是根据现场实测数据建立的,综合考虑了三个误差因素的相互影响和作用,因而具有较高的精度。

This paper presents a new method for compensating the beam shift, beam bend and randon turbulence simultaneously by using multiple regression analysis, a lignment system is described. Experiments show that this method can raise the precision of alignment by 20-80% at different conditions and the accuraey of 10μm/hour within 10 m has been reached.