抄録
Quasi-phase matched (QPM) second-harmonic generation (SHG) device offers various application for blue and ultra-violet (UV) radiations. Advanced poling technology made it possible to realize micron and sub-micron poling geometry in efficient nonlinear materials. Using these techniques, first-order nonlinear gratings have been realized for high power blue and UV SHG. Based on these devices, high power short wavelength laser sources were demonstrated for practical use. Recent progress in this area is reviewed with emphasis on research work of the author's group using bulk and waveguide QPM devices.