Birefringence measurement by four-step phase-shifting method on triple-polarizer plane polariscope

A new four-step phase-shifting method for birefringence measurement based on the plane polariscope is proposed. The plane polariscope to carry this phase-shifting method is characterized by triple polarizers. One fixed polarizer is used as a linearly polarized state generator; the other two rotatable linear polarizers act as phase shifters. The measurement ranges are (0, π) for phase retardation and (−π∕4, þπ∕4) for azimuth angle. Numerical simulation is carried out, and two mica wave plates are tested and evaluated. Compared with other commonly used methods on Senarmont or circular polariscopes, this method has the simplest optical setup and also is free from the errors of quarter wave plates. It has less wavelength dependence and temperature dependence and is expected to be more cost-effective and environmentally robust. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. [DOI: 10.1117/1.OE.52.4.040501] Subject terms: birefringence measurement; phase-shifting; triplepolarizer; plane polariscope. Paper 121820L received Dec. 12, 2012; revised manuscript received Feb. 20, 2013; accepted for publication Mar. 11, 2013; published online Mar. 27, 2013.