Whole field polarization analysis by digital holography with single reference beam

Digital holographic technique has been applied to analyze the spatial distribution of polarization state of light transmitted through anisotropic objects by successive hologram recording using polarization switching of the reference wave by an optical fiber Faraday rotator. For a test object, a quarter wave plate (QWP) is used and the distribution of polarization ellipse over its field is analyzed for various azimuth of the QWP. By inserting a polarizer into a part of the object wave as a reference area, a phase drift of the reference waves caused by polarization switching and environmental disturbances can be estimated and compensated for by using the phase of the known polarization area. The principal axis and ellipticity are calculated and compared with their theoretical values. A good agreement between the experimental and theoretical values is observed. For an application, a photoelastic effect induced in a compressed PMMA specimen is also investigated.