A SPAD-based pixel linear array for high-speed time-gated fluorescence lifetime imaging

A monolithic 64-pixel linear array for Fluorescence Lifetime Imaging applications is presented. Each pixel includes four actively quenched Single Photon Avalanche Diodes, four gated 8-bit counters and is capable of measuring single and double exponential decays. The array has a 34% fill factor, a maximum throughput rate of 320 Mbps, and has been tested up to 40 MHz laser repetition rate. Preliminary fluorescence measurements have been performed obtaining a 6% lifetime precision in 660 mus accumulation time and a very good uniformity among the pixels.