A Compact 32-Channel TCSPC and Time-Tagging Module Supporting Multiple SPAD Array Technologies and Geometries

Time-Correlated Single-Photon Counting (TCSPC) systems with high temporal resolution and multiple channels are essential for applications such as fluorescence lifetime imaging microscopy (FLIM), LiDAR, time-of-flight imaging, and quantum optics. However, existing platforms often provide limited detector compatibility, geometric flexibility, or channel scalability. This work presents a compact multichannel TCSPC platform integrating timing electronics, FPGA-based acquisition, and interchangeable detection heads in a 160×60×60mm3 module. The system employs custom monolithically integrated time-to-amplitude converter (TAC) arrays, providing 32 parallel timing channels. One-to-one acquisition is supported for 32-pixel single-photon avalanche diode (SPAD) arrays, while a 2:1 analog OR-compression stage with digital collision rejection extends compatibility to 64-pixel arrays. Both histogram-based TCSPC and time-tagging modes are implemented on the FPGA. The timing electronics provide a nominal bin width of 0.76 ps over a 12.5 ns full-scale range, with a representative TAC–ADC channel exhibiting approximately 25 ps FWHM timing precision and 0.862% LSB RMS DNL. At the system level, mean timing FWHM values of 68.66 ps and 97.99 ps are measured across the 32×1 custom-technology and 8×8 commercial CMOS SPAD arrays, respectively. These results validate the proposed platform across different SPAD technologies and array geometries, demonstrating a compact and versatile architecture for multichannel single-photon timing applications.