光谱位相相干电场法的参数分析及测量

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１７.７ fs。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１６.８ fs，与ＳＰＩＤＥＲ 的误差比为５．１％，说明了实验的有效性。

Optimization of parameters and measurement on SPIDER

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 filter window and dispersion were analyzed on the optimal selection. When the dispersion and pulse width were given, the time delay τ 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 characterization of Ti:sapphire pulse was measured by using SPIDER. The comparison with autocorrelation measurement showed the validity of experiment.