Abstract

Our goal in this paper is to point out that ultrathin optical films bounded by low- loss biréfringent materials allow an additional type of guided waves that has not been noticed early. For illustrative purposes, we pay attention here to a film of thickness D of an isotropic material with refractive index n/, surrounded by an isotropic material with refractive index n_c and a positive biréfringent crystal, whose ordinary and extraordinary refractive indices are n_os and n_es. The optical axis of the crystal is assumed to lie on the guide plane, forming an angle θ with the waveguide axis, which corresponds to offaxis propagation in an X or Y—cut sample. With the exception of on-axis propagation configurations, waves guided by such an structure are of the hybrid type, with the six field components.

© 1993 Optical Society of America