Annealed proton-exchanged LiNbO_3 waveguides

Abstract
We report characterization of annealed proton-exchanged waveguides in LiNbO3. Effective-mode indices and fundamental-mode intensity profiles were measured for a variety of fabrication conditions. Index profile, depth, and surface refractive-index change were determined versus exchange depth and anneal time and are presented in a universal form. An empirical concentration-dependent diffusion model describing the annealing process is presented. The refractive-index dispersion in proton-exchanged and annealed proton-exchanged waveguides was determined for wavelengths between 0.4 and 1.1 μm.