飞秒脉冲初始脉宽和啁啾对其自相似演化及压缩的影响

采用自相似抛物脉冲放大器对飞秒脉冲直接进行放大,并以低非线性系数的光子带隙光纤作为脉冲压缩器对放大的脉冲进行压缩.通过分步傅里叶方法研究了飞秒脉冲的初始宽度和啁啾对其自相似演化和压缩的影响.研究结果表明脉冲宽度越宽,脉冲自相似演化程度越差,演化脉冲的压缩质量也越差,压缩脉冲宽度较大,且有基座；脉冲的初始啁啾会严重阻碍其自相似演化,并最终影响脉冲的压缩质量；啁啾越大,脉冲的自相似演化结果越差,脉冲的压缩质量也越差；正的啁啾对脉冲的自相似演化的影响比负啁啾的要大.

Influence of Femtosecond Pulse's Initial Width and Chirp on Its Self Similar Evolution and Compression

Femtosecond pulse was directly amplified by self similar parabolic amplifier,and the amplified pulse was then compressed with a photonic bandgap fiber with low nonlinearity.The influences of initial pulse width and the chirp of femtosecond pulse on its self similar amplification and succedent compression were studied by Split-step Fourier Method.The result shows the wider the pulse is,the worse the self similar evolution and compression are; consequently the compressed pulse has a wider pulse width and is also accompanied by a pedestal.It also shows the initial chirp can greatly hold out the self similar evolution,and deteriorate compression quality.And the larger the initial chirp,the worse the self similar evolution.Positive chirp has a larger influence on the self similar evolution than negative chirp.