Analysis of mutually incoherent symmetrical illumination for electronic speckle pattern shearing interferometry

Abstract

A speckle shearing interferometer has been designed using symmetrical mutually incoherent illumination, in an effort to provide measurements of in-plane strain. An analysis of the sensitivity to displacement and strain of this interferometer is presented, together with analysis of the optical phase extraction of the resultant fringe pattern. This interferometer is an improvement on previous designs as it provides information on the in-plane strain separated from components of the displacement. Experimental results provide qualitative data in the form of fringe patterns in support of the theoretical analysis.

Acknowledgments

Juan F. Román is currently with Bayer Diagnostics, however, this work was done during his PhD research under the direction of John R. Tyrer at the Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, and Vicente Moreno, at the Universidade de Santiago de Compostela, Spain.