Periodically-poled LiNbO3 waveguide devices for short-wavelength light generation

We examined and improved the technique to fabricate domain-inverted gratings with period down to 2 μm, and demonstrated a variety of devices with the gratings. We previously demonstrated efficient quasi-phase-matched-second harmonic generation (QPM-SHG) devices for green/blue/ultraviolet light generation and a resonant waveguide QPM-SHG device for higher efficiency. Recently we proposed a waveguide third harmonic generation device in which a QPM-SHG part and a QPM-SFG (sum frequency generation) part are cascaded. In this paper these results are reviewed briefly