Characterization of Polarization Holographic Gratings Obtained on Azopolymer Thin Films by Digital Holographic Microscopy

Polarization diffraction gratings are formed by one-step polarization holographic recording in azopolymer thin films. The evolution of the gratings parameters, such as the modulation of diffraction efficiency and relief depth with regard to different exposure dose is analyzed. Phase-shifting digital holographic microscopy is applied for the measurement of the light-induced polarization diffraction gratings. For the accurate hologram acquisition and reconstruction of the complex amplitude transmitted by the gratings, we performed all-optical (without moving components) phase-shifting implemented within in the imaging system of the digital holographic microscope. The experimental measurement results and theoretical predictions were compared and analyzed.