Paper on SPADs at the NATO Science & Technology organization meeting

A paper titled "SPAD Image Sensors for Quantum and Classical Imaging" by Prof. Edoardo Charbon was published in the STO Meetings proceedings in January 2024.

Paper link: https://www.sto.nato.int/publications/STO%20Meeting%20Proceedings/STO-MP-IST-SET-198/MP-IST-SET-198-C1-03.pdf

Abstract:
Single-photon avalanche diodes (SPADs) have been demonstrated on a variety of CMOS technologies since the early 2000s. While initially inferior to their counterparts implemented dedicated technologies, modern CMOS SPADs have recently matched them in sensitivity, noise, and timing jitter. Indeed, high time resolution, enabled by low jitter, has helped demonstrate the most impressive developments in fields of imaging and detection, including fluorescence lifetime imaging microscopy (FLIM), Förster resonance energy transfer (FRET), fluorescence correlation spectroscopy (FCS), time-of-flight positron emission tomography (TOF-PET), and light detection and ranging (LiDAR), just to name a few. The SPAD’s power of detecting single photons in pixels that can be replicated in great numbers, typically in the millions, is currently having a major impact in computational imaging and quantum imaging. These two emerging
disciplines stand to take advantage of larger and larger SPAD image sensors with increasingly low jitter and noise, and high sensitivity. Finally, due to the computational power required at pixel level, power consumption must be reduced; we thus advocate the use of in situ computational engines, which, thanks of CMOS’ economy of scale and 3D-stacking, enable vast computation density. Some examples of this trend are given, along with a general perspective on SPAD image sensors.