Effect of annealing on proton-exchanged LiNbO₃ waveguides fabricated using stearic acid

Characterization of proton-exchanged optical planar waveguides in z-cut LiNbO₃ fabricated using stearic acid and effects of annealing on the index profile, the waveguide depth, the surface index changed and propagation loss have been studied systematically. Waveguide propagation losses decrease with annealing time and the variation in the surface refractive index and waveguide depth with annealing time follows a power law relationship. The annealing process is shown to be an effective means to improve and modify waveguide properties.