角位移Fabry-Perot干涉测量

提出了一种基于Fabry-Perot板干涉的角位移测量新方法。此方法采用函数近似,只需将初始入射角确定在40°到50°之间,即可由角位移与干涉信号条纹数变化间的函数关系,高精度测量角位移。解决了采用F-P板干涉法测量角位移需精确确定入射光初始角的问题。使用计算机处理采集的干涉信号,对干涉条纹进行细分,实现干涉信号相位测量的高分辨力。理论模拟和实验结果得出本方法可以实现精度为10-5rad数量级的角位移测量。该方法的测量装置采用带尾纤的半导体激光作为光源,由自聚焦透镜准直,出射光束直径为0.5mm,使探测头为小光斑。该装置结构简单,能实现小型化。

Fabry-Perot interferometer for measuring angular displacement

A novel interferometer based on a Fabry-Perot plate is proposed for measuring small angular displacement. The measurement of initial angle of incidence in high accuracy is simplified to keep it between 40 degrees and 50 degrees through approximation of function. A photodiode is used to detect the interference signal. The output signal of the photodiode is processed by a computer. The resolution of phase variation is improved by subdividing the fringes of interference signal. Numerical calculation and experimental results show that the interferometer allows high-accuracy measurements of angular displacements. The sensitivity is of the order of 10-5 rad. A laser diode with pigtail is used as the light source. The output beam is collimated by a GRIN and the diameter of collimated beam is 0.5 mm. The interferometer has a simple structure and can be made compactly.