激光二极管抽运的被动调Q Nd∶GdVO_4激光器

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。

Laser-Diode Pumped Passively Q-Switched Nd∶GdVO4 Laser

Passively Q-switched Nd∶GdVO4 laser performance was investigated by using laser-diode as pump source, and Cr4+∶YAG (Cr4+∶Y3Al5O12), 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.