First Order Quasi-Phase-Matched Second-Harmonic Generation in LiTaO3 Utilizing a Periodic Domain Inversion Created by an External Stress

First order quasi-phase-matching in a proton exchanged LiTaO3 channel waveguide structure is reported, where the periodic domain inversion is created by the application of a periodic compressive stress near the Curie temperature. The processing conditions, driving force, and effects on resulting domain structure is reported, including the observation of domain structures with periods as small as 0.36 μm. A waveguide second-harmonic generation structure with a periodic 3.45 μm domain inversion structure is fabricated and evaluated to quasi-phase-match 420 nm blue light with 840 nm output available from standard laser diode sources.