一种实现高精度稳定Zeeman激光频差的方法

Beat frequency stabilization of a longitudinal zeeman laser

为了使双频激光干涉仪的高精度和可靠性能够在当前急需解决的大尺寸高精度同轴度、直线度测量方面有效的发挥出来，有必要在双频激光干涉仪的信号处理方面采用比相技术，为此，需要稳定Ｚｅｅｍａｎ激光的频差。本文提出一种基于８０９８单片机系统的智能化稳频差方案，不但保证了频差的稳定性，而且每次开机还能自动搜寻频差极值，从而保证了光频的复现性。系统经过实验验证，频差变化小于５ｋＨｚ／５ｈ，工作稳定可靠，可以满足比相的要求。

The double frequency laser interferometer has been widely used in precisionmeasurement.When it is used to measure straightness, the Wollaston prism can not be moved out of thelaser beam.So it can not be utilized to measure axiality. In this paer a new method of stabilizing the beatfrequency of a He-Ne longitudinal Zeeman laser, in which 8098system is used,has been developed.Itcan also seek the maximum of frequency difference automatically,so this guarantees the frequency reproducibility. The maximum of frequency difference is about 600kHz.The change of the beat frequency isno more than 5kHzduring 5 hours.This stability makes it possible to measure the phase between reference signal and measuring signal.Therefore, he interferometer using this beat frequency stabilized HeNe laser can be used to measure straightness and axiality conveniently.