Analysis of Polarization State by Digital Holography with Polarization Modulation

Abstract

The digital holographic technique is applied to analyze the spatial distribution of polarization state of light transmitted through anisotropic objects using an orthogonal linearly polarized reference beam. The polarization orientation of reference beam is switched by an optical fiber Faraday rotator for successive hologram recording. To confirm the principle of polarization analysis, a quarter wave plate (QWP) is used and the distribution of polarization state over the object surface is analyzed for various orientations of the QWP. By providing an area of a known polarization for a part of the object wave as a reference, a phase drift of the reference waves can be evaluated and compensated for using the reference area. The principal axis and ellipticity of polarization ellipse are calculated and compared with their theoretical values. A good agreement between the experimental and theoretical values is observed.