飞秒级超短脉冲光参量转换效率及脉冲特征计算

Calculation of the Conversion Efficiency and Characteristics of Output Pulse of Ultrashort-pulse Optical Parametric Generation

建立了超短脉冲光参量产生过程的理论模型,数值求解耦合波方程组,研究了在飞秒级超短脉冲的光参量产生过程中,泵浦光的强度和脉宽对转换效率、输出脉冲的宽度和不对称度的影响。结果表明:泵浦光越强,光参量产生的转换效率越高,同时脉宽的压窄效应越明显;泵浦光的脉宽越窄,GVM参数和IGVD参数就越大,导致转换效率下降,同时引起输出脉冲的脉宽变大和波形的对称性变差。

The coupled wave equations for ultrashort-pulse optical parametric generation(OPG) are deduced and numerically solved.The influence of the intensity and the duration of pump pulse on the characteristics of ultrashort-pulse OPG are theoretically studied.Our calculation results show that the conversion efficiency of OPG and the features of the generated pulses are greatly affected by the intensity and the duration of pump pulse.The stronger the pump intensity,the higher the conversion efficiency of OPG,and the narrower the signal pulse duration.The narrower the pump pulse duration,the greater the parameters of GVM (group-velocity mismatch among three pulses) and IGVD(intrapulse group-velocity dispersion),the lower the conversion efficiency of OPG and the larger the duration and asymmetry degree of signal pulse.