Periodically-poled LiNbO3 optical parametric oscillator with 55% slope efficiency pumped by a Q-switched Nd : YAG laser

We have demonstrated an efficient quasi-phase matched optical parametric os cillation using periodically poled LiNbO3 of a 40-mm interaction length and 500-mu m thickness. The tuning ranges of signal and idler waves were 1.56- 1.74 mu m and 2.75-3.34 mu m, respectively, for the temperature change of 6 0-230 degrees C. We obtained a 55% slope efficiency for the signal wave and the maximum signal power of 590 mW at a 1.66 W pump power using 1.064-mu m Q-switched Nd:YAG laser with the repetition rate of 1 kHz. The linewidth o f the signal was 0.24-0.35 nm without any controlling element.