Isopachics measurement using immersion method polarization holography: 2

The isopachics of a birefringent object were obtained as a moiré pattern, see Kihara et al., Appl. Opt. 15, 3025 (1976). This paper describes experiments that separate the isopachics of a birefringent object by using the immersion method real-time polarization holography. The sign of the isopachics is accurately determined in real time by inserting a wave front retarder in the optical path of the illuminating beam and observing the shift of the fringe pattern.