Abstract

LiTaO₃ crystal is widely used in many important optic, electro-optic, and acousto-optic applications because of its large coefficients, mechanical and chemical stability, and in addition that large crystal can be grown using Czochralski method. LiTaO₃ has been recognized as an attractive nonlinear material because of its large nonlinear coefficient and high resistance to photorefractive damage. However, it has been scarcely used for second-harmonic generation (SHG) due to its small birefringence. The only way to attain efficient SHG in LiTaO₃ is quasiphase matching (QPM), which is performed in periodically domain-inverted structure. We have proposed fabrication methods for periodically domain inversion in LiTaO₃ and resulted in realizing highly efficient QPM-SHG devices. In this paper, we present proposed three methods to fabricate periodically domain inversion in LiTaO₃ and OPM-SHG devices as a practical frequency doubler for coherent blue-light generation.

© 1995 IEEE