基于含时分步积分算法反演单体MgO:APLN多光参量振荡能量场

Energy conversion of multi-optical parametric oscillation based on time-dependent split-step integration methods in MgO:APLN

针对脉冲抽运机制下多光参量振荡器内1.57μm和3.84μm跨周期参量光的能量耦合过程,利用含时波动方程建立起关于时间的能量转换模型,并运用分步积分法对模型进行求解,获得参量光转换效率.模拟多光参量放大器输出参量光波形,证实逆转换和模式竞争是影响多光参量振荡的重要因素.进一步,模拟外腔多光参量振荡器1.57μm和3.84μm跨周期参量光的输出情况.分别对比不同输出透过率、晶体长度和谐振腔长度下转换效率的模拟值,证实了输出镜透过率影响1.57μm和3.84μm跨周期参量光的转换效率,同时表明外腔多光参量振荡器存在最佳晶体长度和谐振腔长度.基于仿真结果,开展外腔多光参量振荡器实验.1.57μm和3.84μm参量光转换效率实验值与理论值相吻合,证实此方法能精准地反演多光参量振荡器的能量转换过程,为优化多光参量振荡器、提高参量光转换效率提供了理论依据.

In a multi-optical parametric oscillator by pulse pumping,energy conversion process for 1.57μm and 3.84μm parametric light can be expressed by time-dependent wave equations.The split-step integration method is used to solve the equations.By analyzing the simulation results of the output waveform for the multi-optical parametric amplifier,it is confirmed that back conversion and mode competition are the important factors affecting the multi-optical parametric oscillation.The 1.57μm and 3.84μm parametric light in an external cavity multi-optical parametric oscillator are simulated under different output mirror transmittances,crystal working lengths and cavity lengths.The conversion efficiency of 1.57μm and 3.84μm increase with the output mirror transmittance increasing,which means that the conversion efficiency can be adjusted by changing the parametric light transmittance of the output mirror.There exist an optimal crystal working length and a cavity length in the external cavity multi-optical parametric oscillator.The experiment on external cavity multioptical parametric oscillator is carried out.The conversion efficiency of 1.57μm and 3.84μm parametric light are consistent with the theoretical values.The energy conversion process in the multi-optical parametric oscillator can be simulated by this method,which could be used for optimizing the multi-optical parametric oscillator and increasing the parametric conversion efficiency.