Interference of light in diffused and thin-film glass waveguides

An investigation was made of the interference of light in planar optical waveguides formed in barium crown and barium flint glasses by solid-state diffusion of metals and high-frequency sputtering of glasses. Interference between the waveguide and substrate modes was observed in thin-film glass waveguides of near-critical thickness and in some diffused waveguides prepared by the thermal diffusion of silver and copper. The reasons for this interference were analyzed.