Ultra scaling of SPAD arrays for high-speed laser ranging

Ultrasensitive detection of visible light has a wide range of applications, including laser ranging and free-space optical communications. Ultimate sensitivity is achieved when individual return photons are counted with high probabilities of detection, low probabilities of false counts, and high bandwidth. Previously, Vacuum photomultiplier tubes provided good single photon detection sensitivities but with limited bandwidth, while semiconductor solutions provide high bandwidth or high sensitivity, but not both. LightSpin proposes to develop a novel semiconductor solution to bridge the gap between bandwidth and ultimate sensitivity. The approach recognizes ultra-scaling of single photon avalanche diode (SPAD) arrays enables substantial improvements in bandwidth to be achieved. The approach uses GaInP, a wide band gap compound semiconductor with superior characteristics for high speed detection of visible light with low noise. The Phase I goal is to achieve single photon sensitivities at bandwidths approaching 1 GHz, laying the foundation for a Phase II effort to extend the bandwidth to 10 GHz.