Chen Yufan, Wu Xuejuan, Chen Yang, Lin Wenhui, Gu Haojie, Zhang Yuzhen, Zuo Chao
Smart Computational Imaging Laboratory (SCILab), School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Smart Computational Imaging Research Institute (SCIRI), Nanjing University of Science and Technology, Nanjing 210019, China.
Sensors (Basel). 2024 Dec 24;25(1):3. doi: 10.3390/s25010003.
Lens-free on-chip microscopy (LFOCM) is a powerful computational imaging technology that combines high-throughput capabilities with cost efficiency. However, in LFOCM, the phase recovered by iterative phase retrieval techniques is generally wrapped into the range of -π to π, necessitating phase unwrapping to recover absolute phase distributions. Moreover, this unwrapping process is prone to errors, particularly in areas with large phase gradients or low spatial sampling, due to the absence of reliable initial guesses. To address these challenges, we propose a novel biplane phase retrieval (BPR) method that integrates phase unwrapping results obtained at different propagation distances to achieve accurate absolute phase reconstruction. The effectiveness of BPR is validated through live-cell imaging of HeLa cells, demonstrating improved quantitative phase imaging (QPI) accuracy when compared to conventional off-axis digital holographic microscopy. Furthermore, time-lapse imaging of COS-7 cells in vitro highlights the method's robustness and capability for long-term quantitative analysis of large cell populations.
无透镜片上显微镜（LFOCM）是一种强大的计算成像技术，它将高通量能力与成本效益相结合。然而，在LFOCM中，通过迭代相位恢复技术恢复的相位通常被包裹在-π到π的范围内，因此需要进行相位解缠以恢复绝对相位分布。此外，由于缺乏可靠的初始猜测，这种解缠过程容易出错，特别是在具有大相位梯度或低空间采样的区域。为了应对这些挑战，我们提出了一种新颖的双平面相位恢复（BPR）方法，该方法整合了在不同传播距离处获得的相位解缠结果，以实现准确的绝对相位重建。通过对HeLa细胞进行活细胞成像验证了BPR的有效性，与传统的离轴数字全息显微镜相比，其定量相位成像（QPI）精度得到了提高。此外，对体外COS-7细胞的延时成像突出了该方法的稳健性以及对大量细胞群体进行长期定量分析的能力。
