Superconducting nanowire single-photon detectors are set apart from other photon counting technologies above all else by their extremely high speed, with few-ten-ps timing resolution, and recovery times τR≲10 ns after a detection event. In this work, however, we identify in the conventional electrical readout scheme a nonlinear interaction between the detector and its readout which can make stable, high-efficiency operation impossible at count rates even an order-of-magnitude less than τR−1. We present detailed experimental confirmation of this, and a theoretical model which quantitatively explains our observations. Finally, we describe an improved readout which circumvents this problem, allowing these detectors to be operated stably at high count rates, with a detection efficiency penalty determined purely by their inductive reset time.
@article{arxiv.1302.2852,
title = {Readout of superconducting nanowire single-photon detectors at high count rates},
author = {Andrew J. Kerman and Danna Rosenberg and Richard J. Molnar and Eric A. Dauler},
journal= {arXiv preprint arXiv:1302.2852},
year = {2015}
}