Picosecond superconducting single-photon optical detector
2001; American Institute of Physics; Volume: 79; Issue: 6 Linguagem: Inglês
10.1063/1.1388868
ISSN1520-8842
AutoresGregory Goltsman, O. Okunev, G. Chulkova, A. Lipatov, A. Semenov, К. В. Смирнов, B. Voronov, A. Dzardanov, Carlo Kosik Williams, Roman Sobolewski,
Tópico(s)Semiconductor Quantum Structures and Devices
ResumoWe experimentally demonstrate a supercurrent-assisted, hotspot-formation mechanism for ultrafast detection and counting of visible and infrared photons. A photon-induced hotspot leads to a temporary formation of a resistive barrier across the superconducting sensor strip and results in an easily measurable voltage pulse. Subsequent hotspot healing in ∼30 ps time frame, restores the superconductivity (zero-voltage state), and the detector is ready to register another photon. Our device consists of an ultrathin, very narrow NbN strip, maintained at 4.2 K and current-biased close to the critical current. It exhibits an experimentally measured quantum efficiency of ∼20% for 0.81 μm wavelength photons and negligible dark counts.
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