Polarized common path optical heterodyne interferometer for measuring the elliptical birefringence of a quartz wave plate

A novel method based on a polarized optical heterodyne interferometer with a common path feature was proposed and set up. This interferometer was used to measure the phase difference delta(f) of the fast wave of the elliptical polarized eigenstate in the directions of the P and S waves in an elliptical birefringence wave plate. The values of delta(f) are calculated on the basis of the phase difference and the ratio of the amplitude of input polarized Light with the accuracy up to 10(-3). The measurement results provide evidence of the existence of elliptical birefringence in both lambda/4 and lambda/2 quartz wave plates.