应变测量的激光频谱法

现代光学理论证明,Fraunhofer衍射装置为傅里叶频谱分析器。在傅里叶频谱分析器中,当激光正射前焦面的图像时,在其后焦面上形成一个个衍射斑即傅里叶频谱;当前焦面上的图像发生变形时后焦面上的频谱亦发生改变,通过分析频谱的这种改变量就可以获得图像的变形信息。几年前作者根据这一思想首次提出了应变测量的激光频谱法,近来又有了新的进展。本文将对新方法做更详细的阐述和讨论。

Laser Spectral Analysis of Strain Measurement

Modern optical theory has shown that the far field or Fraunhofer Diffraction Equipment is identical to the Fourier Spectral Analyzer. In the Fourier Spectral Analyzer the Fourier spectra or the Fraunhofer diffraction patterns of a graph are formed on the back focal plane when a laser beam is directed on the graph lying on the front focal plane; the Fourier spectra of the graph are also subject to change during the deformation of the graph. Through analyzing the changes of Fourier spectra the deformation of the graph can be obtained. A few years ago, the authors based on the above principles proposeed the technique of strain measurement by laser spectral analysis. Demonstration and discussion will be made in detail in this paper.