Guo Chengfei, Jiang Shaowei, Song Pengming, Wang Tianbo, Shao Xiaopeng, Zhang Zibang, Zheng Guoan
Xi'an Key Laboratory of Computational Imaging, Xidian University, Shaanxi 710071, China.
Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA.
Biomed Opt Express. 2021 Oct 29;12(11):7173-7184. doi: 10.1364/BOE.443528. eCollection 2021 Nov 1.
Multi-height phase retrieval introduces different object-to-detector distances for obtaining phase diversity measurements. In the acquisition process, the slow-varying phase information, however, cannot be converted to intensity variations for detection. Therefore, the low-frequency contents of the phase profile are lost during acquisition and cannot be properly restored via phase retrieval. Here, we demonstrate the use of a coded image sensor for addressing this challenge in multi-height phase retrieval. In our scheme, we add a coded layer on top of the image sensor for encoding the slow-varying complex wavefronts into intensity variations of the modulated patterns. Inspired by the concept of blind ptychography, we report a reconstruction scheme to jointly recover the complex object and the unknown coded layer using multi-height measurements. With both simulation and experimental results, we show that the recovered phase is quantitative and the slow-varying phase profiles can be properly restored using lensless multi-height measurements. We also show that the image quality using the coded sensor is better than that of a regular image sensor. For demonstrations, we validate the reported scheme with various biospecimens and compare the results to those of regular lensless multi-height phase retrieval. The use of a coded image sensor may enable true quantitative phase imaging for the lensless multi-height, multi-wavelength, and transport-of-intensity equation approaches.
多高度相位恢复引入不同的物距与探测器距离以获取相位多样性测量值。然而，在采集过程中，缓慢变化的相位信息无法转换为强度变化用于检测。因此，相位分布的低频内容在采集过程中丢失，并且无法通过相位恢复正确恢复。在此，我们展示了使用编码图像传感器来应对多高度相位恢复中的这一挑战。在我们的方案中，我们在图像传感器顶部添加一个编码层，用于将缓慢变化的复波前编码为调制图案的强度变化。受盲叠层成像概念的启发，我们报告了一种重建方案，使用多高度测量联合恢复复物体和未知编码层。通过模拟和实验结果，我们表明恢复的相位是定量的，并且可以使用无透镜多高度测量正确恢复缓慢变化的相位分布。我们还表明，使用编码传感器的图像质量优于常规图像传感器。为了进行演示，我们用各种生物样本验证了所报告的方案，并将结果与常规无透镜多高度相位恢复的结果进行比较。编码图像传感器的使用可能使无透镜多高度、多波长和强度传输方程方法能够实现真正的定量相位成像。
