Modeling planar leaky optical waveguides.

A simple theoretical model is proposed for a description of light propagation in ion-implanted leaky waveguides. It permits interpretation of existing published experimental results. A single parameter, the imaginary component of the refractive index, is sufficient to describe losses in the barrier. Simple analytical expressions are obtained for both the lateral resonance condition and the confinement coefficient. For each quasiguided mode, we calculate an optimal barrier thickness which gives the lowest attenuation coefficient. Interestingly, for thick barriers, high-order modes give the best confinement coefficient. Our approach can also describe prism-loaded slab type waveguides. [ABSTRACT FROM AUTHOR]