An angle-selective CMOS imager with on-chip micro-collimators for blur reduction in near-field cell imaging

Development of microfabricated imagers placed within the resection bed intraoperatively can significantly improve image-guided surgery. One application is identifying microscopic disease during cancer removal. This class of imagers requires robustness against variations in fluid, blood, and tissue surface profile which vary the distance of the tissue from the imager, causing light from the sample to be incident on the imager at a wide range of angles, thereby blurring the image. This paper addresses this problem by demonstrating an angle-selective imager fabricated in a 0.18um CMOS process, capable of reducing light incident at angles >25° from the perpendicular by >50%.