激光聚焦系统的设计分析

Design and Analysis on laser focusing system.

激光是单色性、干涉性和聚焦性非常好的光源 ,激光器射出的光束是按高斯分布的 ,高斯光束本身存在着作用能够互换的共扼平面的性质。文章应用高斯光束的瞳平面和像平面的共扼关系 ,分析激光聚焦系统的两种总体方案的设计。即当物方高斯光束束腰离透镜的距离l远大于透镜焦距f,f为极小值 ;或l接近于零 ,瑞利距离Z0 远大于透镜焦距时 ,能够获得较小的聚焦束腰。

Laser is a good lamp house possessing of monochromaticity, interference capability and focusing property. The beam of light transmitted by laser is shaped in Gauss′ distribution which can be interchanged in conjugate plane. This paper mainly analyses two scheme designs of focusing system by using the conjugate relation between pupil plane and image plane in Gauss beam. When the distance between Gauss beam waist of object and lens is farther than the lens focus, and the lens focus is minimum; or when the distance is near to zero, and the Rayleigh distance is farther than the lens focus, the less focalized waist can be obtained. These conclusinos provide theoretical instruction to the application of laser devices.