双波长照明下的非干涉相位恢复算法

Non-interence Phase Retrieval Algorithm with Two Wavelength Illumination

针对原有基于强度传输方程(TIE)的非干涉相位恢复技术只适用于单波长条件下近距离传播时相位求解的局限,提出了一种双波长照明条件下的TIE算法.该算法在求解过程中考虑两个波长下相位间的相关约束,并引入了合成波长的概念.同时,考虑到TIE法在远距离传播时相位恢复精度较低的问题,将其与角谱迭代算法结合,提出了一种双波长混合迭代算法.实验结果表明,双波长TIE算法相位恢复图的误差平均值降低到0.191 2;在远距离传播时,双波长混合迭代算法相位恢复图的误差平均值降低到0.220 2.表明所提算法可以在双波长照明下有效地恢复相位信息,并且不受距离的限制.

Aiming at the limitation of the original non-interfering phase retrieval technique based on the Transport of Intensity Equation（TIE）which is only suitable for the short distance regions propagation under single wavelength condition,aphase retrieval algorithm based on TIE method under a two wavelength illumination condition is proposed.The algorithm takes into account the correlation constraints between the two phases under two separate wavelength and the concept of synthetic wavelength is introduced.Meanwhile,considering the limitation of phase retrieval accuracy at longer distance transmission,a two wavelength hybrid iterative algorithm is proposed by combining the aforementioned algorithm with the angular iterative algorithm.The experimental results show that the error of phase diagram retrieved by the two-wavelength TIE algorithm is reduced to 0.191 2 on average;the error of phase diagram retrieved by the proposed two wavelength hybrid iterative algorithm is reduced to 0.220 2 on average.The proposed algorithm can effectively recover the phase information under two wavelength illuminations and is not limited by the distance.