Photon-Counting Arrays for Time-Resolved Imaging

Sensors (Basel). 2016 Jun 29;16(7):1005. doi: 10.3390/s16071005.

Abstract

The paper presents a camera comprising 512 × 128 pixels capable of single-photon detection and gating with a maximum frame rate of 156 kfps. The photon capture is performed through a gated single-photon avalanche diode that generates a digital pulse upon photon detection and through a digital one-bit counter. Gray levels are obtained through multiple counting and accumulation, while time-resolved imaging is achieved through a 4-ns gating window controlled with subnanosecond accuracy by a field-programmable gate array. The sensor, which is equipped with microlenses to enhance its effective fill factor, was electro-optically characterized in terms of sensitivity and uniformity. Several examples of capture of fast events are shown to demonstrate the suitability of the approach.

Keywords: FCS; FLIM; SPAD; fluorescence; fluorescence correlation spectroscopy; fluorescence lifetime imaging microscopy; single-photon avalanche diode.