Leaky-mode propagation in Ti-diffused LiNbO_3 and LiTaO_3 waveguides

Abstract

We have observed leaky-mode propagation in Ti-diffused LiNbO3 and LiTaO3 planar waveguides in nonaxial propagation directions when the optic axis lies in the waveguide plane. For LiNbO3 waveguides, we measure both the leak angle and the loss coefficient as a function of propagation direction and present a theoretical model that quantitatively agrees with our observations. The loss coefficient is expressed in a form that shows the dependence on anisotropy and mode dispersion.