单光束位相反演技术研究

单光束位相反演技术是物体经反射或者透射后,在轴向上对物体进行多平面采样,通过应用基于角谱法传播的迭代位相恢复算法再现振幅和位相的技术。通过仿真和实验分别比较了再现位相与原位相的误差平方和,从而研究位相恢复算法的迭代次数和采样平面数对位相再现的影响。在理论仿真情况下,迭代次数与采样平面数越多,再现位相与原位相的误差平方和就越小,再现效果越好,但在实验中,迭代次数和采样平面数在一定范围内是越多越好,但迭代次数和采样平面数太多会导致实验误差叠加,引入过多噪声,使得再现效果越差。

Phase retrieval technology by a single-beam

A light beam with a plane wave-front is transmitted or reflected from an object. The intensity patterns are sampled. Phase retrieval technology by single-beam wave-front is used to reconstruct the amplitude and phase of the object by processing those intensity patterns using an iterative phase retrieval algorithm based on the angular spectrum propagation. In this paper, by comparing square root error between the reconstructed phase and primary phase, two parameters including the number of iterates and sampled planes are researched on the effects of reconstruction in simulation and experiment. The errors are lower as increasing the number of iterates and sampled planes in simulation. However, in experiment, the increase of the number of iterates and sampled planes reduce the retrieved phase error just in a certain range. Beyond the range, the error would add and then it would introduce noise that will make the reconstruction worse.