Optical damage free guided second harmonic generation in 1% MgO-doped stoichiometric lithium tantalite

Room-temperature cw second-harmonic generation from telecom wavelengths, with 30% W-1 cm(-2) efficiency and second-harmonic power levels up to 41 mW, was achieved in buried waveguides fabricated by reverse-proton exchange in 1% MgO-doped stoichiometric lithium tantalate without any evidence of optical damage. The technology proves suitable for the realization of efficient nonlinear frequency converters and all-optical devices.