Megapixel SPAD arrays for imaging: a versatile tool for quantum experimentalists and consumers alike

Abstract

CMOS SPADs have appeared in 2003 but it is only the availability of deep-submicron SPAD technology that has made megapixel SPAD cameras possible. Large-format SPAD image sensors have enabled more applications and the introduction of proximity sensing is accelerating the process, so much so that today SPADs are in almost every smartphone and the promise is that they will be in every car by 2022. The digital nature of SPADs and the increased density of computation over multiple silicon layers will soon enable deep-learning processors on chip, thus enabling complex processing while reducing power consumption. Another recent trend is the use of SPADs in qubit readout and control, thus making them amenable to interface with quantum processors, due to the capability of operating normally at cryogenic temperatures. The talk will conclude with a technical and economic perspective for SPAD imagers and a vision statement for photon counting in CMOS and other hybrid technologies.