利用频率分辨光学开关(FROG)法测量超短激光脉冲时,使用层叠成像算法能够实现脉冲的超分辨重建。将FROG法测量的迹图在频域中以矩阵形式表达,结合sinc函数在频率轴的延展性质,成功诠释了FROG法的相位编码原理,该分析为超短脉冲的超分辨恢复提供了理论支持。在此基础上,数值仿真演示了对FROG迹图的频率轴和延时轴同时进行欠采样的情形下,利用层叠成像算法实现的相位恢复结果。该结果有助于指导FROG的测量,提高测量的精度,减少测量时间。

The Ptychography algorithm can be implemented to realize the super-resolution reconstruction of ultrashort pulses when the frequency-resolved optical gating (FROG) method is used for their diagnosis. We obtained an arbitrary FROG trace by multiplying matrices, exploited the extending property of “sinc” functions, and then demonstrated the coding phase principle of the FROG method. The proposed analysis provides theoretical support for the super-resolution reconstruction of ultrashort pulses. Furthermore, a numerical simulation revealed the phase recovery results of the Ptychography algorithm with undersampling in both the delay axis and frequency axis of FROG trace. These results are conducive for making the FROG measurement more accurate and less time-consuming.