A system and method for detection, localization and signaling of single photon events and of at least two photons time coincidence events. The system includes at least one array of pixels, each of which includes a photodetector and a front-end electronics, which outputs a digital signal; at least one event detection electronics including: a plurality of digital-to-analog transducers, one for each pixel of the array, configured to convert the digital signal coming from the respective pixel in a corresponding analog signal, which is quantized in amplitude and duration; an analog adder node configured to sum the analog signals coming from the digital-to-analog transducers, obtaining a sum analog signal; and an overall analog-to-digital transducer. The system and method are ultimately configured to output a digital signal if an output signal of an analog adder node exceeds, respectively, a first threshold or the second threshold, allowing event detection, within a time window.