基于MgO:APLN的多光参量振荡器实验研究及其逆转换过程演化分析

Experimental study of multiple optical parametric oscillator based on Mg O:APLN and its evolution analysis of back conversion

对基于Mg O:APLN的多光参量振荡器进行了实验研究.通过优化Mg O:APLN极化结构及参量光耦合输出透过率,在200 k Hz高重复频率1064 nm激光抽运下,通过单极化晶体实现了1.57μm,3.84μm跨周期参量光输出,平均功率分别达到2.4 W和1.31 W,对应光-光转换效率为11.54%和6.25%.同时针对多光参量振荡过程的逆转换现象,通过耦合波方程对其进行了数值演化,并引入"逆转换能量传导区"概念,指出逆转换能量传导区的存在促使弱增益光学参量振荡器的参量光得到二次增强,所得结论与实验结果相符合.

In this paper, a multiple optical parametric oscillator based on MgO：APLN is reported. The polarization structure of MgO：APLN and output coupler transmittance are optimized, with a high repetition rate of 200 kHz and 1064 nm laser pumping. The 1.57 μm and 3.84 μm cross period parameters light output can be achieved by a single poled crystal for the first time. The maximum average output powers of 2.4 W at 1.57 μm and 1.31 W at 3.84μm are obtained, corresponding to optical-optical conversion efficiency of 11.54% and 6.25%, respectively. For the phenomenon of energy back conversion appearing in the multiple optical parametric oscillation process, the numerical evolution of multi-wave coupling process through the coupled wave equations is investigated, and the concept of ＂back conversion in energy transmission area＂ is induced, and indicates that the existence of back conversion in energy transmission area causes the weak gain parameters of optical parametric oscillator to be enhanced twice. The theoretical analyses are basically in agreement with the experimental results.