Fully integrated electronics for high-performance time-resolved imagers with single photon avalanche diode arrays

Time-resolved imaging by means of Single Photon Avalanche Diodes (SPADs) has been subject to a widespread interest in recent years, especially since technological breakthroughs have opened the way to the development of multichannel Time Correlated Single Photon Counting (TCSPC) acquisition systems. Nevertheless, a main drawback of TCSPC has to be taken into account: it is an intrinsically slow technique because it requires the collection of a statistically-significant number of events to build a histogram that accurately reconstructs the time-domain waveform. As a result, the acquisition time needed for imaging can be relatively long. Two main solutions can be adopted to push the speed of a TCSPC measurement: the increment of the acquisition rate of the single channel and the exploitation of a high number of channels operating in parallel. The actual implementation of these solutions requires complex highperformance electronics designed on purpose. In this paper we report and discuss fully-integrated solutions for the development of a high-throughput and high-performance TCSPC acquisition system.