Quasi-phase-matched self-frequency-doubling waveguide laser in Nd:LiNbO/sub 3/

A Nd:LiNbO/sub 3/ quasi-phase-matched self-frequency-doubling waveguide laser is demonstrated for the first time. Fabrication of domain-inverted gratings in Nd:LiNbO/sub 3/ for quasi-phase-matched second-harmonic generation (QPM-SHG) was a key for implementation of the device. A simple fabrication method was found and employed in a prototype device fabrication. The device was optically-pumped at 814-nm wavelength. A laser oscillation took place at 1084 nm and green light emission was obtained at 542 nm by intracavity QPM-SHG.