Opt Lett. 2019 Apr 15;44(8):1976-1979. doi: 10.1364/OL.44.001976.
We report a compact, cost-effective, and field-portable lensless imaging platform for quantitative microscopy. In this platform, the object is placed on top of an image sensor chip without using a lens. We use a low-cost galvo scanner to rapidly scan an unknown laser speckle pattern on the object. To address the positioning repeatability and accuracy issues, we directly recover the positional shifts of the speckle pattern based on the phase correlation of the captured images. To bypass the resolution limit set by the imager pixel size, we employ a sub-sampled ptychographic phase retrieval process to recover the complex object. We validate our approach using a resolution target, phase target, and biological sample. Our results show that accurate, high-quality complex images can be obtained from a lensless dataset with as few as ∼10 images. We also demonstrate the reported approach to achieve a 6.4-mm by 4.6-mm field of view and a half-pitch resolution of 1 μm. The reported approach may provide a quantitative lensless imaging strategy for addressing point-of-care-, global-health-, and telemedicine-related challenges.
我们报告了一种紧凑、经济高效且便于现场使用的无透镜成像平台，用于定量显微镜。在该平台中，物体放置在图像传感器芯片上，而无需使用透镜。我们使用低成本的振镜扫描仪快速扫描物体上的未知激光散斑图案。为了解决定位重复性和准确性问题，我们直接基于捕获图像的相位相关来恢复散斑图案的位置偏移。为了绕过成像器像素尺寸设定的分辨率限制，我们采用子采样的叠层相位恢复过程来恢复复杂物体。我们使用分辨率靶标、相位靶标和生物样本验证了我们的方法。我们的结果表明，通过仅使用约 10 张无透镜数据集可以获得准确、高质量的复杂图像。我们还展示了该方法能够实现 6.4mm×4.6mm 的视场和 1μm 的半节距分辨率。该方法可能为解决即时护理、全球健康和远程医疗相关挑战提供了一种定量无透镜成像策略。
