Periodic domain inversion and generation of blue light in lithium tantalate waveguides

Generation of blue light from small solid-state light sources is a technological challenge with applications in many areas, among others optical data storage. The authors report frequency doubling using third-order quasi-phase matching in periodically domain-inverted lithium tantalate waveguides. Periodic proton exchange followed by heat treatment caused periodic domain inversion and waveguide formation in a single step. Infrared radiation from a dye laser was coupled through the waveguides and second-harmonic generation corresponding to third-order quasi-phase-matching was observed.<>