Investigations Towards the Measurement of Displacement using Lateral Shearing Interferometry and Fourier Fringe Analysis Technique

Abstract

In the present communication we report the measurement of small displacement of reflecting surface (plane mirror) using wedge plate lateral shearing interferometry. With the help of simple mathematical analysis relation between specimen displacement and difference phase is undertaken. Fourier based fringe analysis technique is used for determination of difference phase. Theoretical and experimental investigations are carried out to check the sensitivity of the technique. The detailed discussion regarding sources of errors and uncertainty analysis is also incorporated and the expanded uncertainty is found to be ±0.00236mm. The technique is simple and can be used in industry environment.