Design and characterization of a fast CMOS multiple linear array imager for nanosecond light pulse detections

Active pixel sensors (APS) technology offers performance competitive with charge-coupled device technology, and it offers advantages in on-chip functionality, system power reduction, cost, and miniaturization. In this paper, we present the design and characterization of a fast CMOS APS imager for high-speed laser detections, which can replace streak cameras. It produces intensity information as a function of one spatial dimension and time (I=f(x,t)) from a pixel array with two spatial dimensions. The time information is obtained for the first prototype camera by delaying successively the integration phase for each pixel of the same row. The different noise sources of the APS sensors, such as shot noise due to the photo sensor, thermal noise, and flicker noise due to the readout transistors, and the photon shot noise are presented in order to determine the fundamental limits of the image sensor. The first prototype fast MOS imager (FAMOSI) consists of 64×64 active pixels. The simulation and experimental results show that a conversion gain of 6.73±0.25 μ V/e^- has been obtained with a noise level of 87±3 e^- rms. The power consumption of the chip is 25 mW at 50 frames/s. The time resolution is 0.8 ns for this new concept camera.