高测速双纵模双频激光干涉仪系统的研究

Study on High Measuring Speed Dual-frequency Laser Interferometer with Two Longitudinal Modes

以合适频率的高稳定度电子振荡器信号分别与双纵模热稳频双频激光干涉仪输出的频率过高的测量和参考信号混频,将信号载波频率降至计数器允许频率范围内,得到全交流的高测速双纵模双频激光干涉仪系统。本文给出了高测速双纵模双频激光干涉仪系统光路框图和信号处理框图,并给出了振荡器频率选择的基本公式。所研制系统纵模间隔约728MHz,计数器选用最大允许计数频率10MHz的82c54,振荡器为频率为723MHz的JE0723型介质振荡器。在3m激光测长机上的实验证实:系统分辨率为0.32μm时,最大允许测量速度可达1300mm/s,能满足各种高速运动设备的检测及标定需求。

The frequency of measuring signal and reference signal output by the dual-frequency laser interferometer based on the frequency-stabilized double longitudinal modes He-Ne laser with thermoregulation is too high. The signal with right frequency generated by oscillator of high frequency stability is used to mix them respectively to get transformed signals with low frequency which can be counted, a fully alternating current system with high measuring speed is gained. This paper has shown the schematic diagram of the optical system and signal processing system of the measuring system and the basic formula of the selection of the frequency of oscillator. The mode interval of developed system is 728MHz, the used counter is 82c54, its top counting frequency is 10MHz, the frequency of oscillator is determined as 723MHz. It has been proved by experiments carried out on 3m laser length measuring machine that its top measuring speed is better than 1300mm/s when its resolution is 0.32μm,it can effectively meet the requirements of measuring and calibrating of high speed equipments.