We present a photon-counting detection system at telecom wavelengths that overcomes the difficulties of photon-counting at high rates. Our detection system uses active multiplexing, an array of N detectors, and a 1-by-N optical switch with a control circuit to direct input light to live detectors. We analyze typical bottlenecks in infrared single-photon detectors and optimize switching algorithms for better performance. We conclude that in addition to detection deadtime reduction, the switching algorithm for the multiplexed detectors array should reduce the so-called trigger deadtime, common to any gated detectors. This switching algorithm is shown to scale better than other multiplexed schemes with the number of detectors. Implementing the algorithm reduces overall deadtime by 5x when using just N=2 multiplexed detectors. Our experimental results show the advantage of our improved system as compared to passive multi-detector detection systems and previously reported multiplexed detector array based on a switching algorithm that addresses only detection deadtime and not gate deadtime.
Citation: Review of Scientific Instruments
Pub Type: Journals
Photon Counting, Detector, Down-Conversion, Correlated Photons, Statistical Methods, Multiplexing, Infrared