激光二极管抽运的被动调Q Nd∶GdVO_4激光器

Laser-Diode Pumped Passively Q-Switched Nd∶GdVO_4 Laser

利用激光二极管作为抽运源,分别用Cr4+∶YAG,GaAs和染料片作为饱和吸收体,研究了Nd∶GdVO4激光器的被动调Q特性。Nd∶GdVO4晶体尺寸为4mm×4mm×6mm,掺Nd浓度为1%。利用小信号透过率分别为91%和95%的Cr4+∶YAG,调Q的阈值分别为063W和057W;在抽运功率为369W时,分别得到了脉宽为64ns,80ns,脉冲能量为366μJ,341μJ,重复率为325kHz,378kHz的稳定调Q脉冲。利用580μm厚的GaAs调Q的阈值为039W,在抽运功率为369W时,得到了脉宽为78ns,脉冲能量为215μJ,重复率为366kHz的稳定调Q脉冲。利用初始透过率为70%的染料片调Q获得的脉冲最窄,但是其插入损耗大,抽运阈值高,输出也不稳定。

Passively Q switched Nd∶GdVO 4 laser performance was investigated by using laser diode as pump source, and Cr 4+ ∶YAG (Cr 4+ ∶Y 3Al 5O 12 ), GaAs and dye as saturable absorber, respectively. The laser crystal sample of 4 mm×4 mm×6 mm with 1% Nd concentration was used. For Cr∶YAG with small signal transmission 91% and 95%, the thresholds were 0 63 W and 0 57 W, respectively. At the pump power of 3 69 W, stable laser pulses with 64 ns and 80 ns pulse duration, 3 66 μJ and 3 41 μJ pulse energy, 325 kHz and 378 kHz pulse repetition rate were generated with the two Cr∶YAG saturable absorbers, respectively. The threshold for a 580 μm GaAs wafer was 0 39 W. At the pump power of 3 69 W, stable laser pulses with 7 8 ns pulse duration, 2 15 μJ energy and 366 kHz pulse repetition rate were produced with GaAs saturable absorber. The narrowest Q switched laser pulse could be obtained with a dye wafer with 70% initial transmission. But because of its high insert loss, the threshold was high and the output was not stable.