光谱位相相干电场法的参数分析及测量

Optimization of parameters and measurement on SPIDER

从光谱位相相干电场重构法(SPIDER)的原理出发,实现了算法、讨论时间延迟、光谱剪切量、滤波窗口宽度、色散量等几个方面的优化选取。当展宽器色散和脉冲宽度一定时,脉冲对的时间延迟存在一个最佳取值范围。相对光谱剪切量在5%～15%间,滤波窗口宽度为/3,重构出的位相误差最小。对干涉图取平均来减小噪声的影响。用SPIDER算法还原了脉冲的电场和位相信息,由SPIDER测量的脉冲宽度为17.7fs。同时为了比较,用自相关法测量了同一脉冲,由自相关曲线可估算出脉冲宽度为16.8fs,与SPIDER的误差比为5.1%,说明了实验的有效性。

Based on the spectral phase interferometry of direct electric-field reconstruction （SPIDER）, the spectral phase of femtosecond laser pulse was reconstructed with numerical simulations. Several crucial parameters, such as the time delay, frequency shear, width of fil- ter window and dispersion were analyzed on the optimal selection. When the dispersion and pulse width were given, the time delay r had an optimum range. When the relative spectral shear was 5%-15% and the width of filter window was τ/3 ,the reconstructed phase error was minimum. The noise was reduced by taking mean of the interferograms. The characteriza- tion of Ti.sapphire pulse was measured by using SPIDER. The comparison with autocorrela- tion measurement showed the validity of experiment.