Single-Photon Avalanche Diode Imagers Applied to Near-Infrared Imaging

Abstract

Abstract-Single-photon avalanche diodes (SPADs) can be integrated into large pixel arrays. The aim of this paper is to present a view on how these imagers change the paradigm of wide-field nearinfrared imaging (NIRI). Thanks to the large number of pixels that they offer and to their advanced time-resolved measurement capabilities, new approaches in the image reconstruction can be applied. A SPAD imager was integrated in a NIRI setup to demonstrate how it can improve spatial resolution in reconstructed images. The SPAD imager has a time resolution of 97 ps and a picosecond laser source with an average output power of 3 mW was employed. The large amount of data produced by this new setup could not directly be analyzed with state-of-the art image reconstruction algorithms. Therefore a new theoretical framework was developed. Simulations show that millimetric resolution is achievable with this setup. Experimental results have demonstrated that a resolution of at least 5 mm is possible with the current setup. A discussion about how different characteristics of the SPAD imagers affect the NIRI measurements is presented and possible future improvements are introduced.Index Terms-Inverse problems, near-infrared imaging (NIRI), single-photon detector, time-resolved imaging.

Subdural CMOS optical probe (SCOPe) for bidirectional neural interfacing

“…The use of single-photon avalanche photodiodes (SPAD) has increased in recent years due to their miniaturization and monolithic integration into CMOS imaging arrays( 21 ). They have been explored in many biophotonics applications including endoscopic FLIM( 22 ), super-resolution microscopy( 23 ), NIROT( 24 ), and PET( 25 ). The SCOPe system incorporates a custom CMOS ASIC that consists of an array of 192×256 monolithic SPAD detectors ( Fig.…”

Silicon-Based Avalanche Photodiodes: Advancements and Applications in Medical Imaging

“…These detectors demonstrate excellent operating characteristics and cost-effectiveness. The reviewed results illustrate the clear potential for integrating group IV materials APDs and SPADs with silicon CMOS technology for low-cost, high data rate detector array imaging in the visible, NIR, and SWIR bands [87][88][89]. These advancements are crucial for emerging biomedical applications.…”

New frontiers in time-domain diffuse optics, a review

“…With these solutions, the maximum conversion rate (expressed as counts per second, cps) was limited between few tens of kcps to about 100 kcps. 173 A very interesting alternative is represented by the so-called "digiSiPM," which is similar to a standard SiPM, but integrates one (or sometimes more) TDC. 165 Notwithstanding the differences between these two technologies, they show similar performances in terms of minimum timing jitter (∼10 ps), nonlinearity (∼1%), maximum count rate (few Mcps), power consumption (tens of watts), and cost (few k€/channel).…”