| 摘要 |
PROBLEM TO BE SOLVED: To surely improve S/N of the data acquire by a fringe scan method, independent of fluctuation of environment. SOLUTION: In an interference measurement method, a fringe scan which changes optical path difference between reference light and the light to be detected is performed by a plurality of times. The data for change in interference fringe pattern that occurs at each fringe scan is sampled. A plurality of sampled data are averaged to reduce a random noise. Here, phase deviation between the plurality of data is suppressed before the average. So, the S/N of the data after averaging is surely improved independent of fluctuation of environment. COPYRIGHT: (C)2003,JPO |
