提出一种分束调制技术来实现高精度单次曝光相位恢复成像,将待测光束用二维光栅分成一组彼此相同的衍射光束簇,并同时入射到一个结构已知的调制板上,当调制板为弱衍射物体时,在探测器上形成一组彼此相分开的衍射斑阵列。联合这些衍射光斑和弱衍射物体的透射函数,可通过一次曝光迭代计算出待测量光束的强度和相位信息,同时具有Gergberg-Saxton算法等单次曝光方法的成像速度快和相干叠层衍射成像算法等扫描成像技术的高信噪比和高精度等优点,对X射线成像和高功率激光光束在线监测等领域有重要的实用价值。

A novel high-precision phase retrieval imaging method based on beam splitting amplitude modulation is proposed. The incident beam to be measured is split into many diffracted replicas by a two dimensional grating, and these diffracted beams are illuminated on a modulation plate with known structure. When the modulation plate is weakly scattered, the diffraction patterns formed on the detector are clearly separated with each other. Both the amplitude and phase of incident beam can be reconstructed iteratively by using the recorded diffraction patterns and the known structure of the modulation plate. This method has the high imaging speed of Gergberg-Saxton algorithm and the high precision of ptychographical iterative engine and potentially can be applied for X-ray imaging and online detection of high power laser.