氦镉激光器的噪音研究

Noise Characteristics of He-Cd Laser

本文在实验上研究了氦镉激光噪音的起因和特性,得到氦镉激光嗓音的起因是多重的。行走辉纹、气压差及镉浓度波都是产生噪音的重要原因。气压差及镉浓度波可使噪音增大很多倍,浓度波主要增强了低频噪音。适当增大激光管内平均镉浓度和采用扩散迴路后,可显著降低激光噪音,获得大功率低噪音的氦镉激光器。

The origin and characteristics of He-Cd laser noise are investigated. It is concluded that the noise is of a multi-fold origin. Pressure difference and Cd concentration fluctuation are factors as important as moving striations in causing He-Cd laser noise. Pressure difference and Cd concentration fluctuation may cause the noise to increase many times with the latter mainly enhancing the noise in the low frequency range. By using a return path and appropriately increasing the average Cd concentration in the laser tube, the laser noise can be remarkably reduced and a low noise and high output power He-Cd laser can be obtained.