基于多纵模泵浦光的光参量放大过程的理论分析

摘要

In this study,the coupled-wave equation for three-wave mixing optical parametric amplification was modified.Based on this model,the influence of the multi-longitudinal modes of the pump on the signal gain and the signal amplification bandwidth as compared with that for a single-mode case has been investigated.The results show that,when the pump light power remains stable,the gain is higher when the multi-longitudinal mode rather than a single-longitudinal mode pump power for parametric amplification is adopted.However,the multi-mode gain band width is not necessarily wider than that of single-mode,even when the best noncollinear angle and crystal length are available.Therefore,the single-longitudinal mode of the pump should be used as the energy source of the signal amplification.%通过改变三波混频参量放大的耦合波方程,利用这一模型、数值计算出多纵模泵浦光对放大信号光增益以及增益带宽的影响,并与采用单纵模泵浦光情况下进行比较.结果表明,当泵浦光功率不变时,采用多纵模泵浦光进行参量放大比单纵模泵浦光情况下产生的增益大.但是,在相同的泵浦光强下,即使是选用最佳非共线角和最佳的晶体长度,参量放大过程获得的多模增益带宽不能保证比单模增益带宽宽.因此,参量放大过程应采用单纵模泵浦光作为放大信号的能量来源.