Improved multiplexed infrared single photon detectors
Sergey V. Polyakov, Valentina Schettini, Ivo Pietro Degiovanni, Fabrizio Piacentini, G. Brida, Alan L. Migdall · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2008
We discuss a scheme for a photon-counting detection system that overcomes the difficulties of photon-counting at high rates at telecom wavelengths. Our method uses an array of N detectors and a 1-by-N optical switch with a control circuit to direct input light to live detectors. We conclude that in addition to detection deadtime reduction, the multiplexed switch also reduces so-called trigger deadtime, common to infrared photon counting detectors. By implementing the new algorithm we obtain an overall deadtime reduction of a factor of 5 when using just N=2 multiplexed detectors. In addition to deadtime reduction, our scheme reduces afterpulsing and background counts (such as dark counts). We present experimental results showing the advantage of our system as compared to passive multi-detector detection systems and our previous active multiplexing system that only reduced detection deadtime.