Controlling the anisotropy of holographic polymer-dispersed liquid-crystal gratings

In this work we investigate the optical properties of electrically switched transmission gratings fabricated holographically using polymer-dispersed liquid-crystal (PDLC) materials. We have found that the PDLC mixture can be used to control the diffractive properties of the liquid-crystal composite gratings. In one limit the gratings are highly isotropic and in the other limit the gratings are highly anisotropic with a large birefringence. The experimental results are compared to theories that include the birefringence of the grating. From theoretical fits to the experimental data, measurements of the liquid-crystal distribution and alignment are obtained.