Short-And Long -Term Stability In Proton Exchanged Lithium Niobate Waveguides

We describe fabrication conditions which produce proton exchanged waveguides with long and short term index stability. We present also the surface index change and effective diffusion coefficients associated with exchange in melts of varying concentration, from pure benzoic acid to mixtures containing up to 4 Mole % lithium benzoate. Infrared absorption measurements supporting our explanation for the causes of index instability are presented.