A CMOS Image Sensor for Fluorescence Lifetime Imaging

In this paper, a CMOS image sensor for fluorescence lifetime imaging (FLIM) is presented. The fluorescence lifetime is a powerful tool to analyze molecules because the fluorescence lifetime reflects a molecule's structure, dynamics, and environments. The proposed CMOS FLIM sensor consists of pixel array to realize the sifting ability for fluorescence, noise canceling column readout amplifiers, and output buffers. The pixel has a photodiode and an image intensifier to sift fluorescence from the excited light pulses. A prototype CMOS FLIM sensor with 320(H) times 80(V) pixels is designed and implemented in 0.18 mum CMOS technology. The results show that the CMOS FLIM sensor has the ability to sift fluorescence from the excited light pulses using a blue and an ultraviolet light-emitting diodes. It also shows that the CMOS FLIM sensor can measure the lifetime in a wide range of fluorescence lifetime.