High-power, blue-light generation in a dual-structure, periodically poled, stoichiometric LiTaO3 crystal

High-power blue light was generated from a diode-side-pumped Q-switched 1319 nm Nd:YAG laser with a periodically poled, stoichiometric LiTaO3 (PPSLT) crystal. The PPSLT sample used in this experiment consists of two segments in series: the first segment has a period of 14.08 mu m for the second harmonic generation (SHG) and the second segment has periods of around 4.6 mu m for the generation of blue light by mixing fundamental and SH. An average power of 466 mW of a 440 nm blue light was obtained at the fundamental power of similar to 5.4 W with a conversion efficiency of 8.6%. The output power fluctuated by 3% over a half-hour period. This result indicates that our scheme is a practical method to construct a reliable compact blue laser.