Single-photon avalanche diode arrays for fast transients and adaptive optics

An instrumentation based on a silicon monolithic array of 60 photon counters [single-photon avalanche diode array (SPADA)] for state-of-the-art measurements of fast transient phenomena and adaptive optics (AO) is presented. The fabricated solid-state photon counters are rugged, easy to be integrated in the optical system, free from read-out noise, and provide very fast frame rates (> 10 kHz) and nanosecond electronic gating. The detection electronics includes an integrated active-quenching circuit (AQC) for each pixel of the array. The real-time data-processing board is implemented into a field programmable gate array (FPGA) and a digital signal processor (DSP) and is configurable for dealing with different applications: acquisition and processing of two-dimensional (2-D) images with fast frame rate and extraction of the curvature wavefront for adaptive optics applications. The optical and electrical characterization of the detectors and the associated electronics is reported.