Doppler振镜正弦调制多光束激光外差二次谐波测量角度的方法

Second harmonic multi-beam laser heterodyne measurement for small angle based on oscillating mirror sinusoidal modulation

提出了一种多光束激光外差测微小角度的新方法.基于激光外差技术和Doppler效应,通过做简谐振动的Doppler振镜对不同时刻入射光的正弦调制,把待测角度信息加载到外差信号的频率差中,经信号解调后可以得到待测角度参数值,经加权平均处理可以提高待测角度的测量精度.利用这种新方法,通过Matlab仿真了平面标准镜不同入射角的模拟结果,表明该仿真结果的最大相对误差小于0.789677%.

In this paper,we propose a novel method of multi-beam laser heterodyne measurement for small angle based on sinusoidal modulation of simple harmonic motion oscillating mirror.By using the Doppler effect and heterodyne technology,by loading the information about small angle into the frequency difference of the multi-beam laser heterodyne signal,by using the frequency modulation of the oscillating mirror,this method can give many values of small angle after the multi-beam laser heterodyne signal demodulation simultaneously.Processing these values by weighted-average,small angle can be obtained accurately.This novel method is used to simulate measurement for small angle by MATLAB,the obtained result shows that the relative measurement error of this method is just 0.789677%.