Timing performance of a digital SiPM prototype measured with a picosecond injection laser

Abstract: The DESY digital silicon photomultiplier (dSiPM) is a monolithic detector based on complementary metal-oxide-semiconductor (CMOS) single-photon avalanche diodes (SPADs) and features a fully digital readout. The dSiPM prototype was characterized using a picosecond injection laser. Different contributions to the time resolution from both SPADs and digitization electronics are quantified. The dSiPM achieves a temporal resolution of approximately 50 ps under optimal conditions, while localized charge deposition with the laser revealed in-pixel variations of the time resolution linked to the SPAD layout. Combining fast timing with a pixelated readout, the device is a promising candidate for 4D-tracking detectors and other precision timing applications.