Intensity histogram CMOS image sensor for adaptive optics

We present a high-speed CMOS active pixel sensor (APS) image sensor with focal plane histogram computation. The 128×128 4-transistor active pixel sensor array produces cumulative intensity histograms, at the focal-plane, with speeds in excess of 10,000 frames per second for low-latency, realtime control applications without the need for pixel digitization of external processing. In addition, an on-chip 10-bit column parallel analog-to-digital converter with a read noise of 0.6LSB and negligible fixed pattern noise facilitates conventional imaging operations and data acquisition. Each pixel occupies 19.5μm×19.5μm with a fill factor of 43%. Power consumption is 1.5mW during imaging mode and 4.6mW in high-speed histogram mode. Applications include real-time adaptive optics control for laser communications.