Characterization of proton-exchanged waveguides in MgO:LiNbO_3

We report the fabrication and characterization of proton-exchanged waveguides in MgO-doped LiNbO(3), a high-optical-damage-threshold material. Results indicate waveguide characteristics similar to those of waveguides fabricated in undoped LiNbO(3) except for slower diffusion rates and freedom from etching of the y face when pure benzoic acid is used as a proton source. An optical-damage threshold of 70 kW/cm(2) was measured at 0.5145 microm in a MgO:LiNbO(3) waveguide, corresponding to a factor-of-2 improvement over undoped LiNbO(3).