相位恢复是指利用直接测量得到的强度分布恢复相位从而重建波函数。为了能够在已知强度信息的情况下最大限度地恢复相位,结合强度传输方程提出一种基于整体变分的相位恢复算法:首先在一致性照明的情况下建立相位恢复模型,然后把相位恢复问题转化为带有整体变分正则化项的图像能量泛函极值问题,再使用有限差分牛顿法求出相位的最优解。该算法只需要测量临近空间平面上的光波的空间强度即可从强度图像中恢复相位信息,避免了由于干涉法要求光源的空间和时间连续所造成的分辨率、敏感性等问题。实验表明在恢复相位的同时可以保持良好的边缘。
Phase retrieval refers to the use of direct measurement of intensity distribution to restore the phase and then reconstruct the wave function. A phase retrieval based on total variation with transport-of-intensity equation is presented to obtain phase information as much as possible. First the phase retrieval model is established in the case of uniform illumination, and then the problem is translated into minimum of energy functional with total variation regularization, and the finite difference Newton' s law is used to seek an optimal solution. 0nly the measurements of the spatial intensity of the optical wave in closely spaced planes perpendicular to the direction of propagation are needed and the sensitivity and resolution issues because of the requirements of interferometry techniques put on the spatial and temporal coherence of the optical source are avoided. The experiments show that information in the edge is kept when conducting phase retrieval.