光参量效应中低阶色散对超短高斯脉冲展宽的影响

以宽度为50 fs的超短脉冲和负单轴晶体CsLiB6O10(CLBO)为例,对非线性光学晶体中低阶群速度色散(GVD)导致的超短高斯脉冲和超高斯脉冲的脉冲展宽进行了理论分析.在光参量相互作用过程中,对初始无啁啾和有啁啾调制的超短高斯脉冲的脉冲展宽机制和因素进行了数值计算,得出群速度色散导致超短脉冲的寻常光比非寻常光脉冲展宽更严重;波长越短,脉冲展宽越大;当晶体长度等于色散长度时,脉冲宽度增加为初始时的2倍,色散长度越短,超短脉冲展宽越明显.

Influence of Low Order Dispersion in Optical Parametric Effect on Ultra-Short Gaussian Pulse Broading

Pulse-width expansion of an ultra-short Gaussian pulse in nonlinear optical crystal because of low order group velocity dispersion(GVD) was theoretically analyzed.Optical parametric interaction processes of the CsLiB_6O_(10)(CLBO) crystal with a negative uniaxial and(50 fs) ultra-short Gaussian pulse have been considered.Mechanism of ultra-short Gaussian pulse broading with or without initialization chirp modulation was numerically calculated.The pulse-width is expanded heavier in ordinary light than that in extraordinary in short wavelengths.The shorter pulse wavelength,the heavier pulse-width expanded.When the crystal length is equal to the crystal dispersion length,the pulse-width has been expanded 2 times than the initialization.Also,the shorter the dispersion length is,the more obviously the pulse-width is expanded.