一种可用于离面位移测量的光路的优化设计

为了实现对复杂三维物体表面轮廓、小空间内物体的纵向位移或振动等测量，有必要研制高分辨力、非接触的光学检测系统。由于激光多普勒技术具有动态响应快、线性度好、非接触、测量精度高等特点而优先被用于复杂三维物体离面位移的测量。但是物体表面散射光的多普勒信号非常微弱，因此解决信号的强度、信噪比则是实现测量的关键。研究了激光多普勒技术及散射光相位的无规变化的统计规律，设计出一种空间分辨力很高的参考光路，将它用于固体离面位移测量效果很好，其相对误差为0．3％。

Optimization of Optical System Capable of Off-Surface Displacement Measurement

To achieve the measurement for complicated three-dimensional object surface outline and the longitudinal displacement or vibration of object within a small space, it′s necessary to develop optical detection system with high resolution and non-contact. Laser Doppler technology is preferentially applied in longitudinal displacement measurement of complex three-dimensional object because it has high accuracy, quick dynamic response, good linearity, great measuring range and is noncontact. However, the signal got from the scattered light of object measured is faint, so improving the intensity and signal-to-noise ratio of the signal are pivotal. Laser Doppler technique and statistic law of random changing of scattered light phase are studied and a reference optics with high spatial resolution is designed. The measurement result is satisfying when the system is applied to the off-surface displacement measurement, with a relative error of 0.3%.