SPAD Imagers in Biophotonics Review

Arxiv.org paper "Single-photon SPAD imagers in biophotonics: Review and Outlook" by Claudio Bruschini, Harald Homulle, Ivan Michel Antolovic, Samuel Burri, and Edoardo Charbon from EPFL and TU Delft presents an excellent overview of the recent advances in the field:

"Single-photon avalanche diode (SPAD) arrays are solid-state detectors offering imaging capabilities at the level of individual photons, with unparalleled photon counting and time-resolved performance. This fascinating technology has progressed at very high pace in the past 15~years, since its inception in standard CMOS technology in 2003. A host of architectures has been explored, ranging from simpler implementations, based solely on off-chip data processing, to progressively "smarter" sensors including on-chip, or even pixel-level, timestamping and processing capabilities. As the technology matured, a range of biophotonics applications has been explored, including (endoscopic) FLIM, (multi-beam multiphoton) FLIM-FRET, SPIM-FCS, super-resolution microscopy, time-resolved Raman, NIROT, and PET. We will review some representative sensors and their corresponding applications, including the most relevant challenges faced by chip designers and end-users. Finally, we will provide an outlook on the future of this fascinating technology."