Toward ultra-fast time-correlated single-photon counting: A compact module to surpass the pile-up limit

Time-Correlated Single-Photon Counting (TCSPC) is an excellent technique used in a great variety of scientific experiments to acquire exceptionally fast and faint light signals. Above all, Fluorescence Lifetime Imaging (FLIM), it widely recognized as the gold standard record sub-nanosecond transient phenomena with picosecond precision. Unfortunately, TCSPC has intrinsic limitation: avoid so-called pile-up distortion, have been historically carried out, limiting acquisition rate below 5% excitation frequency. In 2017, we demonstrated that such limitation can be overcome if detector dead time exactly matched period, thus paving way unprecedented speedup FLIM measurements. this paper, present first single-channel system implements novel proposed methodology modern experimental setups. To achieve goal, designed compact detection head, including custom single-photon avalanche diode externally driven by fully integrated Active Quenching Circuit (AQC), featuring finely tunable short reset time. The output timing signal extracted using precision Pick-Up (PUC) fed newly developed module consisting mixed-architecture Fast Time Amplitude Converter (F-TAC) followed high-performance Analog-to-Digital Converters (ADCs). Data are transmitted real-time Personal Computer (PC) at USB 3.0 for specific elaboration. Preliminary results show new suitable implementing technique, achieving, indeed, high along count 40 Mcps.