用于外腔倍频激光的旋光滤波设计与分析

The Analysis of the Optical Design for Extra Cavity Frequency-Doubled Laser Based on the Optical Rotatory Dispersion Effect

为了得到纯净的单色倍频光,依据石英晶体的旋光特性,利用石英晶体和起偏棱镜的组合,给出了一种用于将外腔倍频激光中的基频光去除的旋光滤波设计.石英晶体的厚度只要满足使倍频光与基频光的旋光角之差为π/2的奇数倍,就能滤除基频光而获取纯净的倍频光.利用Origin软件分析了石英晶体的厚度误差对滤光性能的影响,结果表明:厚度误差在±0.02 mm以内时,对滤波效果的影响可以忽略.

In order to obtain the monochromic frequency-doubled laser, an optical design, which can select the fundamental laser out of the extra cavity frequency-doubled laser, is designed by using the quartz crystal and the polarizer according to the crystal＇s optical rotatory dispersion effect. When the rotation angle has a difference of （2n＋ 1） π/2（n = 0, 1, 2, 3,…） between the frequency-doubled laser and the fundamental laser, this design works well. The origin software analyzes the effect of the thickness deviation on the design＇s performance. Results show that the filtering effect on the fundamental laser is good when the thickness deviation is within ±0.02 mm.