We demonstrate lensfree holographic microscopy on a chip to achieve ~0.6 µm spatial resolution corresponding to a numerical aperture of ~0.5 over a large field-of-view of ~24 mm2. By using partially coherent illumination from a large aperture (~50 µm), we acquire lower resolution lensfree in-line holograms of the objects with unit fringe magnification. For each lensfree hologram, the pixel size at the sensor chip limits the spatial resolution of the reconstructed image. To circumvent this limitation, we implement a sub-pixel shifting based super-resolution algorithm to effectively recover much higher resolution digital holograms of the objects, permitting sub-micron spatial resolution to be achieved across the entire sensor chip active area, which is also equivalent to the imaging field-of-view (24 mm2) due to unit magnification. We demonstrate the success of this pixel super-resolution approach by imaging patterned transparent substrates, blood smear samples, as well as Caenoharbditis Elegans.
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机译：我们在芯片上演示了无透镜全息显微技术，以实现〜0.6 µm的空间分辨率，相当于在〜24 mm 2 的大视场中的〜0.5数值孔径。通过使用大孔径（〜50 µm）的部分相干照明，我们可以得到具有单位条纹放大率的低分辨率无透镜行内全息图。对于每个无透镜全息图，传感器芯片上的像素大小限制了重建图像的空间分辨率。为了避免这种局限性，我们实现了基于亚像素移动的超分辨率算法，以有效地恢复物体的高分辨率数字全息图，从而允许在整个传感器芯片有效面积上实现亚微米的空间分辨率，这也是等效的由于单位放大倍数，导致成像视角（24 mm 2 ）变大。我们通过对带图案的透明底物，血液涂片样本以及秀丽隐杆线虫进行成像，证明了这种像素超分辨率方法的成功。
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