Diffraction measurement and analysis of slanted holographic polymer dispersed liquid crystal

In this article, slanted holographic polymer dispersed liquid-crystal films are prepared by using a single-prism interferometer. Their diffraction characteristics are measured at various incident angles. Based on the coupled-wave theory of diffraction efficiency and incident angles, the grating period, film thickness, and slanted angle of the volume grating are derived. A good agreement is demonstrated between the experimental and theoretical results, and supported by scanning electron microscopy observation. The electrical switching behavior of the grating is also described. The diffraction efficiency changes from 65% to a stable value of 10% at an electric field of 33 Vμm. On the other hand, based on the theoretical prediction of diffraction efficiency, the optimum film thickness and Bragg grating period are determined, which sheds light on the implementation of our experiments.