用激光测量微小应变和位移是基于这一事实而成为可能,就是激光是单色相干光,因而由光的波动本性产生的现象易于观察和利用。一般类型的激光应变计利用两束光的干涉。比如,据 Vali 介绍,它可在千米量级距离上检测地球本身的应变,准确度达1×10~(-12)。本文描述的方法利用单缝夫琅 It is possible to measure minute strain and displacement with a laser based on the fact that the laser is a monochromatic coherent light and thus the phenomenon caused by the fluctuating nature of the light is easy to observe and utilize. The general type of laser strain gauge utilizes the interference of two beams of light. For example, according to Vali, it can detect the earth’s own strain at a distance of kilometers, with an accuracy of 1 × 10 ~ (-12). The method described here utilizes a single slit Fraunhofer