2開口法によるレーザスペックル干渉計の測定精度

抄録

This paper describes the measuring accuracy of the laser speckle interferometer using a double-aperture plate for measuring the in-plane displacement of moving object. In this measuring system, the interference fringes are detected by a CCD linear image sensor, and the in-plane displacement is determined by calculating the correlation coefficient using the interference fringes detected before and after motion. The visibility of interference fringes, the speckle noise and the deformation of laser speckle and interference fringes are discussed experimentally and theoretically on their influence upon the measuring accuracy. From the results obtained, the measuring accuracy is improved by detecting the interference fringes two dimensionally, and the average of measuring error less than 0.15 μm is obtained.