SPAD arrays for parallel photon counting and timing

We present a detection module based on a linear array of Single-Photon Avalanche Diodes (SPAD) made in a standard CMOS technology. The monolithic chip is employed both to count photons at very high frame-rate (up to 4,000,000 frames/s, with 250 ns time tagging resolution) and to mark photon arrival time with 50 ps timing precision. The device is ideal for applications involving very weak optical signals in the visible (350-800 nm) spectrum and requiring either high-speed imaging (photon counting), as in fluorescence correlation spectroscopy and confocal microscopy, or precise time tagging (photon timing) of individual photons, as in fluorescence lifetime imaging of biological samples, high-speed linear imaging, spectrophotometry, and Time-of-Flight (ToF) ranging applications.