A 0.18μm CMOS single-photon sensor for coaxial laser rangefinders

This paper introduces a low-noise single-photon sensor in a 0.18 μm CMOS technology for scanning-based coaxial optical rangefinders. At the core of the sensor, macro pixels consisting of 10×10 single-photon detectors enable time-of-flight measurements by taking advantage of temporal and spatial correlations. Unlike conventional silicon photo-multipliers, or multi-pixel photon counters, our sensor features a pulse-shaping and summing stage that accurately resolves the number of quasi-simultaneous photon detections. Sensor characterization data are reported. When mounted on a practical rangefinder setup, the sensor enables distance measurements up to 50 meters with 1σ repeatability error lower than 26 cm throughout the range, using 10 laser pulses.