【摘要】 用计算机仿真模拟了高强度飞秒激光抽运下的光参量放大 (OPA)过程 ,着重讨论了高阶非线性效应对参量转化效率和波形的影响。为了抑制高阶非线性效应对放大信号光波形的调制 ,改善波形质量 ,防止信号光的能量倒流回抽运光 ,并为进一步从抽运光中抽取出尽可能多的能量 ,提高参量转化效率 ,引入了适当的相位失配以抵消高阶非线性效应。利用级联非线性相移从理论上解释了这一物理原因更多还原

【Abstract】 The optical parametric amplification of femtosecond pulse at high pumping intensity is numerically simulated by computer.The effect of cubic nonlinearity on conversion efficient of the high intensity pump pulse and the envelopes of signal pulse are studied in detail. A suitable phase mismatch is introduced to compensate the nonlinear phase mismatch induced by cubic nonlinearity. The compensation can counteract the modulation on the signal pulse on count of cubic nonlinearity and prevent the energy converting from the signal back to pump in three wave interaction. So, higher optical conversion efficiency and better quality of amplificated signal can be gotten. An explicit explanation with cascaded nonlinear phase shift is presented.更多还原