数字微镜器件(DMD)作为空间光调制器,有着高调制速度、高精度的优势,可对照明光进行振幅调制或相位调制,广泛应用于相位成像系统中。利用DMD对照明光振幅进行随机编码调制,通过数值仿真分析DMD加载随机编码图案时最小调制单元尺寸、开/关占比对相位成像的影响,利用差值映射迭代算法实现光场重建。通过实验验证了基于数值仿真分析所得的参数可以更快的迭代速度、更少的测量次数完成振幅与相位的恢复,本文方法对于视场为4.3 mm×4.3 mm的物体的重建分辨率可达6.9 μm。

Digital micro-mirror devices (DMDs) as spatial light modulators, have the advantages of high modulation speed and accuracy and can perform amplitude or phase modulation for illumination light, which are widely used in phase imaging systems. In this paper, a DMD is used for the random coding modulation of illumination light amplitude. We simulate the influences of the smallest modulation unit and switch ratio on phase imaging when random coding patterns are loaded on the DMD. Then we use a difference mapping iterative algorithm for light field reconstruction. Furthermore, it is experimentally verified that based on the parameters obtained via numerical simulation, we can retrieve amplitude and phase with a higher iteration speed and a fewer measurement times. In addition, for an object with the field of view of 4.3 mm×4.3 mm, the reconstruction resolution reaches 6.9 μm.