Diffractive properties of highly birefringent volume gratings: Investigation

We have performed a detailed comparison of the predictions of coupled-wave theories of isotropic and anisotropic volume gratings. It is shown that material birefringence can dramatically modify the diffractive properties of volume gratings. The predictions of the coupled-wave theories have also been compared with the diffractive properties of volume gratings fabricated with polymer-dispersed liquid crystals. It is shown that a coupled-wave theory that includes the effects of the birefringence of the liquid crystal must be used to explain the diffraction properties of these highly anisotropic gratings. Information can be obtained about the alignment of the liquid crystal within the composite gratings from comparisons of theory and experiment.