在激光二极管(LD)泵浦的Nd:YVO4激光器中,采用石墨烯分散液作为可饱和吸收体,分别实现1064 nm和1342 nm激光的被动调Q;获得平均输出功率为0.52 W,脉宽为7.7 ns,重复频率为105 kHz的1342 nm调Q脉冲序列和平均输出功率为0.62 W,脉宽为6.06 ns,重复频率为138 kHz的1064 nm调Q脉冲序列。测量石墨烯分散液对低功率连续激光的吸收系数与入射功率之间的关系,结果表明样品对1342 nm和1064 nm激光均存在可饱和吸收,但是对1342 nm激光吸收的饱和光强较低,由此分析1064 nm和1342 nm调Q脉冲的差别。

Passive Q-switching of a diode pumped Nd:YVO4 laser at 1064 nm and 1342 nm were realized respectively by using graphene dispersion liquid as a saturable absorber. The 1342 nm pulse train with 7.7 ns pulses duration, 0.52 W average power and 105 kHz repetition rate and the 1064 nm pulse train with 6.06 ns pulse duration, 0.62 W average power and 138 kHz repetition rate were achieved respectively. The absorption coefficients of the graphene dispersion liquid for 1064 nm and 1342 nm at the different input power of CW laser were measured. The results indicated that graphene dispersion liquid achieved absorption saturation at 1342 nm and 1064 nm laser, but saturation intensity at 1342 nm was lower than at 1064 nm, thus the differences of Q-switched laser pulses between 1342 nm and 1064 nm was analyzed.