Wu Xuejuan, Sun Jiasong, Zhang Jialin, Lu Linpeng, Chen Rong, Chen Qian, Zuo Chao
Opt Lett. 2021 May 1;46(9):2023-2026. doi: 10.1364/OL.421869.
We propose a lensfree on-chip microscopy approach for wide-field quantitative phase imaging (QPI) based on wavelength scanning. Unlike previous methods, we found that a relatively large-range wavelength diversity not only provides information to overcome spatial aliasing of the image sensor but also creates sufficient diffraction variations that can be used to achieve motion-free, pixel-super-resolved phase recovery. Based on an iterative phase retrieval and pixel-super-resolution technique, the proposed wavelength-scanning approach uses only eight undersampled holograms to achieve a half-pitch lateral resolution of 691 nm across a large field-of-view of 29.85, surpassing 2.41 times the theoretical Nyquist-Shannon sampling resolution limit imposed by the pixel size of the sensor (1.67 µm). We confirmed the effectiveness of this technique in QPI and resolution enhancement by measuring the benchmark quantitative phase microscopy target. We also showed that this method can track HeLa cell growth within an incubator, revealing cellular morphologies and subcellular dynamics of a large cell population over an extended period of time.
我们提出了一种基于波长扫描的无透镜片上显微镜方法，用于宽场定量相位成像（QPI）。与先前的方法不同，我们发现相对大范围的波长多样性不仅能提供信息以克服图像传感器的空间混叠，还能产生足够的衍射变化，可用于实现无运动、像素超分辨的相位恢复。基于迭代相位检索和像素超分辨率技术，所提出的波长扫描方法仅使用八个欠采样全息图，就在29.85的大视野范围内实现了691 nm的半间距横向分辨率，超过了由传感器像素尺寸（1.67 µm）施加的理论奈奎斯特 - 香农采样分辨率极限的2.41倍。我们通过测量基准定量相位显微镜目标证实了该技术在QPI和分辨率增强方面的有效性。我们还表明，该方法可以在培养箱内跟踪HeLa细胞生长，揭示大量细胞群体在较长时间内的细胞形态和亚细胞动态。
