Phase-matched second-harmonic generation at 440 nm in a LiNbO₃ -Gd₃Ga₅O₁₂ waveguide with a tunable stimulated Raman source

Using a tunable stimulated Raman source, we have observed second-harmonic generation in the blue in a sputtered LiNbO3 film deposited on Gd3Ga5O12. With the choice of Gd3Ga5O12 as a substrate, it becomes possible to both phase-match a large range of fundamental wavelengths as well as have an excellent epitaxial quality surface. The SHG efficiency for the TMω0 → TM2ω2 phase matched conversion process is estimated to be ∼ 10-4. © 1981.