声光-GaAs双调Q c-Nd:GdVO4/KTP激光特性

采用激光二极管（LD）泵浦c轴切割的Nd:GdVO4 晶体，声光调制器作为主动调Q开关，GaAs饱和吸收体作为被动调Q开关，实现了声光-GaAs主被动双调Q、KTP内腔倍频0.53 μm绿激光运转，获得了双调Q绿激光的平均输出功率、脉冲宽度、峰值功率与泵浦功率的依赖关系。为了比较单一声光主动调Q、GaAs被动调Q、声光-GaAs主被动双调Q激光脉冲波型的对称性，定义了脉冲前沿上升时间与脉冲后沿下降时间的比值为对称因子来描述脉冲波型的对称性，对称因子越接近1意味着脉冲的对称性越好。实验结果表明，与单一调Q激光相比，双调Q绿激光产生的脉冲波型前后沿更对称、脉冲宽度更窄、峰值功率更高。

Double Q-switched c-cut Nd:GdVO4/KTP green laser with acoustic-optic modulator and GaAs saturable absorber

By simultaneously using both active and passive Q-switched in the same cavity, a diode-pumped doubly Q-switched intracavity-frequency-doubled c-cut Nd:GdVO4/KTP green laser was realized with acoustic-optic(AO) modulator and GaAs semiconductor saturable absorber. The average output power, the pulse width and the peak power of green laser versus the pump power were obtained. In order to compare the pulsed symmetry of AO singly actively Q-switched, GaAs singly passively Q-switched and AO-GaAs doubly Q-switched lasers, a symmetric factor was defined to describe the temporal symmetry of the pulses, whose value was equal to the rise time divided by the fall time of the pulse. The closer to 1 the symmetry factor was, the more symmetric the pulse shape was. The experimental results show that green laser pulse generated by the doubly Q-switched c-cut Nd:GdVO4/KTP has better symmetric pulse shape, narrower pulse width and higher peak power.