SPAD Figures of Merit for Photon-Counting, Photon-Timing, and Imaging Applications: A Review

Abstract

Single-photon avalanche diodes (SPADs) emerged as the most suitable photodetectors for both single-photon counting and photon-timing applications. Different complementary metal-oxide-semiconductor (CMOS) devices have been reported in the literature, with quite different performance and some excelling in just few of them, but often at different operating conditions. In order to provide proper criteria for performance assessment, we present some figures of merit (FoMs) able to summarize the typical SPAD performance (i.e., photon detection efficiency, dark counting rate, afterpulsing probability, hold-off time, and timing jitter) and to identify a proper metric for SPAD comparisons, when used either as single-pixel detectors or in imaging arrays. The ultimate goal is not to define a ranking list of best-in-class detectors, but to quantitatively help the end-user to state the overall performance of different SPADs in either photon-counting, timing, or imaging applications. We review many CMOS SPADs from different research groups and companies, we compute the proposed FoMs for all them and, eventually, we provide an insight on present CMOS SPAD technologies and future trends

Single-photon avalanche diode imagers in biophotonics: review and outlook

“…Table 1 summarizes the most important properties of SPADs and compares them across the SPAD-based imagers reported in Table 2). A number of parameters are used to describe the performance of a single SPAD device [7]. The most important is the photon detection probability (PDP), representing the avalanche probability of the device in response to a photon absorption at a given wavelength.…”

A multipixel diffuse correlation spectroscopy system based on a single photon avalanche diode array

“…Active pixel sensors (APSs) have detection efficiency in the near infrared typically higher than SPAD sensors (about 50% for APS vs 15% for SPADs ). Nevertheless, the advantage of a SPAD camera is the single photon sensitivity that allowed us to work with very short integration times (1 μs) and low count rate per frame (less than 10 photons).…”

“…Nevertheless, the advantage of a SPAD camera is the single photon sensitivity that allowed us to work with very short integration times (1 μs) and low count rate per frame (less than 10 photons). This would not be possible with a CMOS camera, which has no negligible readout noise .…”

Ultra Low Noise CMOS Image Sensors

“…Such a device must have an input-referred read noise negligible compared to a single electron. Among the state-of-the-art imaging devices, single photon detectors may appear to be the best candidate for such an application [96]. Historically, micro-electronics could not provide readout chains with noise levels as low as deep sub-electron.…”