Strain Gauges by variation of differential birefringence

Abstract

The strain-gauge here after described is a purely optical device which makes possible to determine the strains by measuring differential birefringence between two elliptically polarized light beams. Measurements on dielectric material are more performing with this optical strain gauge than with a conventional electrical one. Sensitivities can reach 5.10-6 for strain measurements and one micron for transverse displacements.