Differential Laser Interferometer Extending Optical Path Difference (2nd Report)

Stability and Reliability of a Displayed Value

Abstract

When compared with an usual Michelson interferometer, the laser interferometer in this study has an advantage of the good stability of a displayed value because the prisms in the interferometer make a pair of them and the optical paths are arranged symmetrically. In this study it isclarified with the theoretical analyses and experimental results that the stability is better by about 10 times than the Michelson interferometer. The reliability of a measured value of length has also been checked, comparing the value with the result obtained by a commercial type of ×10 extender device.