Fabrication of 0.7 µm2 ridge waveguide in ion-sliced LiNbO3 by proton-exchange accelerated chemical etching

We fabricated low-loss ridge waveguides of 1.0 × 0.7 µm 2 cross-sectional area in ion-sliced LiNbO 3 crystals by chemical etching accelerated in proton-exchanged regions. Strong light confinement was obtained at 1.55 µm wavelength. The waveguides are effective in implementing efficient and compact nonlinear-optic wavelength conversion devices.