基于低噪声PSD的光线偏转测量方法研究

Study of Optical Probe Beam Deflection Measurement Method Based on Low Noise PSD

采用两个分离式的反向并联的光电位置敏感探测器(PSD),设计了一种新型光电位置敏感传感系统,用于光线偏转的测量。在该系统中,使用一个透镜来提供光学增益并限制探测器的入射角。这种器件对光斑位移的频率响应是非常好的,而且这种分离式的设计能够使电子放大器具有很低的固有热噪声。以氦-氖激光器的标点噪声通过传感器所得到的测量值作为频率函数能够得到更高的精度,更适用于光线偏转角度的测量。

A new optical position sensor is designed using two discrete position sensitive detectors（PSDs） electrically connected for optical probe beam deflection measurement. A lens is used to provide optical gain and control the incident angle of the detector. The response of the device to displacements of an optical spot is better and the discrete photodiode design enables simpler electronic amplification with inherently less electrical noise than the commoner. Measurements of the pointing noise of a focused He-Ne laser made by the sensor as a function of frequency demonstrate higher sensitivity and suitability for optical probe beam deflection experiments.