基于Nd∶YAP偏振特性的电光调Q激光器

摘要

用具有偏振特性b轴切割的Nd∶ YAP激光晶体,在脉冲激光二极管阵列侧面抽运的同时,作为电光调Q的起偏器件,代替同样功能的格兰-福科棱镜.以LiNbO3晶体作为电光晶体,平-平直腔进行实验,在延迟时间150 μs时,在抽运到阈值增益的4倍时,获得了1.02 mJ,70 ns的1341 nm激光脉冲.实验表明,用Nd∶YAP晶体代替格兰-福科棱镜作为电光调Q的起偏检偏器件,可以获得较佳的调Q效果,与理论计算相比,能量降低18％,脉宽增加44 ns,吻合较好；插入格兰-福科棱镜,能量下降25％,脉宽增加28％.该方法可减小腔内损耗,缩短脉宽,为设计制备大功率新型脉冲激光器提供了依据.%Nd: YAP laser crystal with good polarization property is pumped by pulse laser diode array. An electro-optical crystal LiNbO3 and flat-flat cavity are used as polarizer and replace the Grand-Foucault prism at the same time. The 1341 nm laser pulses with 70 ns pulse width and 1.02 mJ energy are obtained under the condition that the delay time is 150 μs and pumping power is 4 times more than threshold gain. Experiments show that the Nd:YAP crystal in place of Grand-Foucault prism as the polarizer of the electro-optic Q-switch can get better Q-switch effect. Compared with the theoretical calculation, the energy decreases by 18% and pulse width increases by 44 ns. When inserting Grand-Foucault prism,the energy is reduced by 25% and pulse width increased by 28%. This Q-switch method can reduce the cavity loss and shorten the pulse width. It is helpful for the design of new high-power pulsed laser.