We present an image sensor incorporating angle-selective gratings for resolution enhancement in contact imaging applications. Optical structures designed in the CMOS metal layers above each photodiode form the angle-selective gratings that limit the sensor angle of view to $\pm$18$^{\circ }$, rejecting background light and deblurring the image. The imager is based on a high-gain capacitive transimpedance amplifier pixel using a custom 11fF MOM capacitor, achieving $\text{8.2}\;\text{V s}^{-1} \text{pW}^{-1}$ sensitivity. The pixel includes a leakage current minimization circuit to remove signal-dependent reset switch leakage and the corresponding dark current is $\text{14}\;\text{aA}/{\mu }\text{m}{^2}$. The resulting 4.7 mm by 2.25 mm sensor (80 by 36 pixels) is designed specifically for intraoperative cancer imaging in order to solve the pervasive challenge of identifying microscopic residual cancer foci in vivo, where they can be removed. We demonstrate imaging and detection of foci containing less than 200 cancer cells labeled with fluorescent biomarkers in 50 ms with signal-to-noise ratios greater than 15 dB and the detection of microscopic residual tumor in mice models. The absence of large optical elements enables extreme miniaturization, allowing manipulation within a small, morphologically complex, tumor cavity.

中文翻译：

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用于体内显微癌症检测的芯片级角度选择成像仪

我们提出了一种结合了角度选择光栅的图像传感器，以提高接触式成像应用中的分辨率。在每个光电二极管上方的CMOS金属层中设计的光学结构形成了角度选择光栅，该角度选择光栅将传感器的视角限制为$ \ pm $18岁$ ^ {\ circ} $，拒绝背景光并消除图像模糊。该成像器基于高增益电容互阻放大器像素，并使用定制的11fF MOM电容器，可实现$ \ text {8.2} \; \ text {V s} ^ {-1} \ text {pW} ^ {-1} $灵敏度。该像素包括一个漏电流最小化电路，以消除与信号有关的复位开关漏电流，并且相应的暗电流为$ \ text {14} \; \ text {aA} / {\ mu} \ text {m} {^ 2} $。最终的4.7 mm x 2.25 mm传感器（80 x 36像素）是专门为术中癌症成像设计的，目的是解决识别微观残留癌灶的普遍挑战体内，可以将其删除。我们展示了在50毫秒内信噪比大于15 dB的影像学和检测到的含有少于200个用荧光生物标记物标记的癌细胞的病灶以及小鼠模型中微观残留肿瘤的检测。由于没有大型光学元件，因此可以实现极小的微型化，从而可以在形态复杂的小肿瘤腔内进行操作。