[1] Brosnan S J, Byer R L. Optical parametric oscillator threshold and linewidth studies. IEEE J. Quant. Electron., 1979, QE-15(6):415～431

[2] Zhang J Y, Huang J Y, Shen Y R et al.. Optical parametric generation and amplification in barium borate and lithium triborate crystals. J. Opt. Soc. Am. (B), 1993, 10(9):1758～1764

[3] Xu Zuyan, Kong Yufei, Zhou Yi et al.. Narrow linewidth, naosecond pulsed pulsed optical parametric oscillator with a compound cavity. Chin. Phys. Lett., 1998, 15(2):112～115

[4] Laenen R, Wolfrum K, Scilmerier A et al.. Parametric generation of femtosecond and picosecond pulses for spectroscopic applications. J. Opt. Soc. Am. (B), 1993, 10(11):2151～2161

[5] Huang Liu, Zhao Yu, Wang Li. Study on square wave pulsewidth variable solid state laser. Chin. J. Lasers (B), 1999, 8(2):116～120

[7] Yariv A, Louisell W H. theory of the optical parametric oscillator. IEEE J. Quant. Electron., 1966, QE-2(9):418～424