编码衍射图样的相位检索

Phase retrieval from coded diffraction patterns

摘要:

经典的迭代相位检索方法具有抗噪性能差、不 能收敛到全局最优解等缺点；而基于相位割(PC)的最优化相位检索技术通过精确的分离振幅 和相位变量, 将相位检索问题转化 为二次约束的凸规划问题,理论上可以保证在相差全局相位因子条件下收敛到全局最优解。 本文提出用更结构 化和更“很少随机的”的三元与八元掩膜编码衍射图样(CDP),求解PC以获得丢失的 相位。模拟实验首先测试 一维复信号,分别比较不同掩膜重构的成功率。其次,比较它们对二维分子图像的重构结果 。实验结果表 明,本文方法可以获得比传统的基于二元掩膜的方法更好的重构结果。将恢复的相位分 布加载到所搭 建的基于Si基液晶(LCOS)的光学重构系统中,产生的CDP证明了所提方法的正确性。

Abstract:

The classical iter ative phase retrieval method has the disadvantages of poor anti-noise performance,and can not conver ge to the global optimal solution.The optimization of phase retrieval technology via PhaseCut (P C) transforms the phase retrieval problem into quadratic constrained convex programming problem,and get s the global optimal solution up to global phase.Some more structured and less random ternary mas ks and octonary masks are used to code the signal of interest to acquire diffraction patterns which ca n recover the missing phase information by solving PhaseCut.Simulations are firstly performed to test the o ne dimensional complex signal and compare the success rates of reconstruction using different masks.Secondly, the reconstruction results of two dimensional molecular images are compared for different masks.The results sh ow that the method can obtain better reconstruction results than the traditional method which is based on binary masks.Moreover, the recovered phase distributions are loaded to the optical reconstruction syste m based on liquid crystal on silicon (LCOS).The diffraction pattern of real experiment proves the effectivene ss of the proposed method.