A highly damage-resistant Zn:LiNbO/sub 3/ ridge waveguide and its application to a polarizationindependent wavelength converter

We have fabricated a periodically poled ridge waveguide using a liquid phase epitaxy (LPE)-grown Zn:LiNbO/sub 3/ substrate. The waveguide can confine both the transverse electric and transverse magnetic mode. Its strong resistance to photorefractive damage enables stable parametric amplification. We demonstrate polarizationindependent wavelength conversion using polarization diversity in a single waveguide.