College of Mechatronics Engineering and Automation, National University of Defense Technology, Precise Engineering Laboratory, Changsha 410073, China.
Appl Opt. 2008 Nov 10;47(32):6079-87. doi: 10.1364/ao.47.006079.
Phase retrieval is a wavefront sensing method that uses a series of intensity images to reconstruct the wavefront. The resolution of phase retrieval testing is limited mainly by the resolution of intensity images captured by CCD cameras. A subpixel phase retrieval method is presented to retrieve the wave field at subpixel resolution by using the information of a sequence of low-resolution images captured along the propagation direction. In this method, the sampling interval for the wave field under test is smaller than the CCD pixel size in phase reconstruction. The wave field is recovered at subpixel resolution by utilizing the energy conservation relationship between CCD pixels and their subpixels by the subpixel phase retrieval (SPR) algorithm. Numerical experiments have shown that more than a fourfold resolution enhancement can be achieved. The method has also been studied in some experiments under noisy and off-axis conditions. A mirror surface testing experiment was conducted to demonstrate the performance of SPR in the real world. The results of these experiments have shown the effectiveness and robustness of this method. SPR allows low-resolution images to be used to retrieve high-resolution wave fields and will be useful in testing wave fields from large objects.
相位恢复是一种波前传感方法，它利用一系列强度图像来重建波前。相位恢复测试的分辨率主要受电荷耦合器件（CCD）相机所采集强度图像分辨率的限制。提出了一种亚像素相位恢复方法，通过利用沿传播方向采集的一系列低分辨率图像的信息，以亚像素分辨率恢复波场。在该方法中，用于测试波场的采样间隔在相位重建中小于CCD像素尺寸。通过亚像素相位恢复（SPR）算法利用CCD像素与其亚像素之间的能量守恒关系，以亚像素分辨率恢复波场。数值实验表明，可实现四倍以上的分辨率增强。该方法还在一些有噪声和离轴条件的实验中进行了研究。进行了镜面测试实验以证明SPR在实际中的性能。这些实验结果表明了该方法的有效性和稳健性。SPR允许使用低分辨率图像来恢复高分辨率波场，并且在测试大物体的波场时将很有用。
