Nb-diffused LiTaO3 optical waveguides: Planar and embedded strip guides

Abstract

Previous results on dielectric optical waveguides made by diffusing niobium into LiTaO3 have been extended. It is shown that the propagation constants of the thin-film waveguide modes can be accurately calculated assuming that the refractive index decreases as the square of the distance into the film. Low-loss single-mode embedded strip guides made by electron resist masking techniques are also described.