正交增益型被动调Q激光器的设计与实现

Design and implementation of orthogonal gain type passively Q-switched laser

为了改善被动调Q激光器输出不稳定的现象,利用Nd:YVO_4具有增益方向性的特点,使用电光晶体将线偏振光光矢量方向旋转90°,实现腔内增益突变,进而实现被动调Q稳定输出。利用该方法,在LD连续泵浦Nd:YVO_4被动调Q实验中,当耦合输出镜反射率为80%,饱和吸收体初始透射率为83.06%,泵浦功率为22 W时,输出功率为4.68 W,调Q序列脉冲的重复频率为49.16 k Hz,脉冲宽度为26.28 ns。并且在泵浦功率从10~22 W的情况下,获得了稳定的被动调Q激光输出。脉冲幅度波动性低于±2.4%,脉冲时间波动性低于±5%,重复频率的不稳定性低于1%,光光转换效率斜效率达到21.27%,斜效率为34%。

In order to improve the stability of the passively Q-switched pulses, the gain orientation of the Nd：YVO_4 was taken advantage and an electro-optic crystal was used to rotate the line polarized light vector by 90°, then the intracavity gain mutation can be realized, thereby stable output of the passively Q-switched was realized. Through this method, when the reflectivity of the coupling output mirror was 80% and the initial transmittance of the saturated absorber was 83.06%, the output power reached 4.68 W at a given pump power of 22 W, high repetition rate output with repetition frequency of 49.16 k Hz and the pulse width of 26.28 ns was obtained in the experiment of LD continuously pumped Nd：YVO_4 passively Q-switched. In the case of the pump current from 10 W to 22 W, a stable passive Q laser output was obtained. The pulse-to-pulse amplitude fluctuation was less than ±2.4%. The inter-pulse timing jitter of the Q-switched pulse train was found to be less than ±5%. The instability of repetition rate was less than 1%. For a slope efficiency of 34%, the corresponding optical-to-optical conversion efficiency reached 21.27%.