Prism-coupled excitation of Dyakonov-Tamm waves

The prism-coupled excitation of Dyakonov-Tamm waves guided by the planar interface of a homogeneous, isotropic dielectric material and a periodically nonhomogeneous sculptured nematic thin film (SNTF) was investigated. The excitation of Dyakonov-Tamm waves was identified by correlating a high-absorptance band in the plots of absorptance vs. the incidence angle and the direction of propagation in the interface plane with the solutions of the underlying canonical boundary-value problem. Dyakonov-Tamm waves were found to have a much wider angular existence domain than Dyakonov waves, and broader absorptance peaks than both the Dyakonov and Tamm waves in the plots of absorptance vs. the incidence angle.