High-efficiency integrated readout circuit for single photon avalanche diode arrays in fluorescence lifetime imaging

In recent years, lifetime measurements by means of theTime Correlated Single Photon Counting(TCSPC) technique have led to a significant breakthrough in medical and biological fields. Unfortunately, the many advantages of TCSPC-based approaches come along with the major drawback of a relatively long acquisition time. The exploitation of multiple channels in parallel could in principle mitigate this issue, and at the same time it opens the way to a multi-parameter analysis of the optical signals, e.g., as a function of wavelength or spatial coordinates. TheTCSPC multichannel solutions proposed so far, though, suffer from a tradeoff between number of channels and performance, and the overall measurement speed has not been increased according to the number of channels, thus reducing the advantages of having a multichannelsystem. In this paper, we present a novel readout architecture for bi-dimensional, high-densitySingle Photon Avalanche Diode(SPAD) arrays, specifically designed to maximize the throughput of the wholesystem and able to guarantee an efficient use of resources. The core of thesystem is a routing logic that can provide a dynamic connection between a large number ofSPAD detectors and a much lower number of high-performance acquisition channels. A key feature of our smart router is its ability to guarantee high efficiency under any operating condition.

Source: Review of Scientific Instruments - November 23, 2016 Category: Physics Authors: G. Acconcia, A. Cominelli, I. Rech and M. Ghioni Source Type: research