Fabrication of Proton-Exchange Waveguide Using Stoichiometric for Guided Wave Electrooptic Modulators with Polarization-Reversed Structure

Optical waveguides were fabricated on z-cut stoichiometric LiTaO3 (SLT) by using the proton-exchange method. The surface index change for the extraordinary ray on the SLT substrate resulting from the proton exchange was 0.017, which coincided well with congruent LiTaO3 substrates. The proton exchange coefficient in the SLT was 0.25×10？12cm2/s. The application of the SLT waveguide to a quasi-velocity-matched travelling-wave electrooptic modulator with periodically polarization-reversed structure is also reported.