Xu Yiqing, Ren Zhibo, Wong Kenneth K Y, Tsia Kevin
Opt Lett. 2015 Aug 1;40(15):3595-8. doi: 10.1364/OL.40.003595.
We investigate the fundamental limitation of the full-field retrieval of optical pulses based on a time-equivalent Gerchberg-Saxton (GS)-like algorithm, in which the Fourier transformation of the temporal signal is performed by the group velocity dispersion (GVD) of optical fibers. The insufficient knowledge of the input pulse intensity fundamentally limited by the bandwidth of the photodetector influences the accuracy of the retrieved phase using the algorithm. To this end, we propose a modified GS algorithm, which involves multi-step intensity-only measurements, to mitigate this limitation. By studying the influence of spectral phase and amplitude modulations on the retrieval error, we show that the modified GS algorithm demonstrates a significant improvement in phase retrieval accuracy. More importantly, we anticipate the present study will provide valuable insight in understanding how the spectral variation generally influences the recovery accuracy in time-stretch-based GS algorithm, and thus identify its potential applications, particularly for those requiring ultrafast measurements.
我们研究了基于类似时间等效格尔奇贝格 - 萨克斯顿（GS）算法的光脉冲全场检索的基本限制，其中时间信号的傅里叶变换由光纤的群速度色散（GVD）执行。受光电探测器带宽根本限制的输入脉冲强度的知识不足会影响使用该算法检索相位的准确性。为此，我们提出了一种改进的GS算法，该算法涉及多步仅强度测量，以减轻这种限制。通过研究光谱相位和幅度调制对检索误差的影响，我们表明改进的GS算法在相位检索精度方面有显著提高。更重要的是，我们预计本研究将为理解光谱变化通常如何影响基于时间拉伸的GS算法中的恢复精度提供有价值的见解，并从而确定其潜在应用，特别是对于那些需要超快测量的应用。
