Tetsuo HARIMOTO^*, Boku YO, and Kosuke UCHIDA

Faculty of Engineering, University of Yamanashi, Kofu 400-8511, Japan

(Received April 4, 2012; Accepted June 12, 2012)

We report the quantitative relationship between the phase-matching condition and the surrounding temperature in a critical phase-matching second-harmonic generation of a Q-switched Nd:YVO₄ laser with a high repetition rate. The thermal effect can be effectively compensated for by appropriately changing the phase-matching angle with respect to the surrounding temperature of a nonlinear optical crystal. A stable wavelength conversion from the 1064 nm fundamental to the 532 nm second harmonic in a type-I critical phase-matching lithium triborate crystal is experimentally achieved and the corresponding conversion efficiency up to 70% is obtained.

Key words: second-harmonic generation, phase-mismatching angle, Q-switched Nd:YVO₄ laser

^*E-mail address: harimoto@yamanashi.ac.jp