LINBO3 WAVE-GUIDE QUASI-PHASE-MATCHING 2ND-HARMONIC GENERATION DEVICES WITH FERROELECTRIC-DOMAIN-INVERTED GRATINGS FORMED BY ELECTRON-BEAM SCANNING

The characteristics of the formation of LiNbO3 ferroelectric-domain-in verted gratings using electron-beam scanning were examined and discuss ed for application to waveguide quasi-phase-matching second-harmonic-g eneration (SHG) devices. It was found that the domain inversion tended to occur in segmented regions and the inversion width was thinner nea r the crystal surface than inside the crystal. The dependence of the S HG efficiency on the grating structure was examined theoretically. Pro totype devices for green and blue light generation were fabricated and the device performance was examined. Normalized SHG efficiencies as h igh as 50%/W and 70%/W, respectively, were obtained in green and blue light generation devices of 3.3 mm length. The experimental results we re discussed in comparison with the theoretical results.