A 500 × 500 Dual-Gate SPAD Imager With 100% Temporal Aperture and 1 ns Minimum Gate Length for FLIM and Phasor Imaging Applications

In this article, we report on SwissSPAD3 (SS3), a 500 $\times$ pixel single-photon avalanche diode (SPAD) array, fabricated in 0.18- notation="LaTeX">$\mu \text{m}$ CMOS technology. sensor, introduce novel dual-gate architecture with two contiguous temporal windows, or gates, guaranteed by the circuit to be nonoverlapping and covering totality of sensor’s exposure period. The gates can adjusted resolution 17.9 ps, minimum measured gate width is 0.99 ns; our knowledge, shortest reported date among large-format SPAD imagers. dual-channel mode, burst frame rate 49.8 97.7 kframes/s single-channel mode. A 2690-MB/s PCI express (PCIe) interface has been added data acquisition framework, enabling continuous operation at approximately 44 88 kframes/s. Due optimizations gate-signal tree, achieved significant reduction skew variation, which negligible respect jitter. These improvements, along sub-10-cps dark count (DCR) per 50% maximum photon detection probability (PDP), result sensor particularly well suited for fast fluorescence lifetime imaging microscopy (FLIM) experiments, demonstrate reduced dispersion versus single-gated sensor.