Single-Photon Avalanche Diode CMOS Sensor for Time-Resolved Fluorescence Measurements

A single-photon avalanche diode-based pixel array for the analysis of fluorescence phenomena is presented. Each 180 x 150 mu m(2) pixel integrates a single photon detector combined with an active quenching circuit and a 17-bit digital events counter. On-chip master logic provides the digital control phases required by the pixel array with a full programmability of the main timing synchronisms. The pixel exhibits an average dark count rate of 3 kcps and a dynamic range of over 120-dB in time uncorrelated operation. A complete characterization of the single photon avalanche diode characteristics is reported. Time-resolved fluorescence measurements have been demonstrated by detecting the fluorescence decay of quantum-dot samples without the aid of any optical filters for excitation laser light cutoff.