A cascade switching superconducting single photon detector
Mikkel Ejrnaes, Roberto Cristiano, Orlando Quaranta, S. Pagano, Alessandro Gaggero, F. Mattioli, Roberto Leoni, B. Voronov, Gregory N Gol'tsman · Applied Physics Letters · 2007
We have realized superconducting single photon detectors with reduced inductance and increased signal pulse amplitude. The detectors are based on a parallel connection of ultrathin NbN nanowires with a common bias inductance. When properly biased, an absorbed photon induces a cascade switch of all the parallel wires generating a signal pulse amplitude of 2mV. The parallel wire configuration lowers the detector inductance and reduces the response time well below 1ns.