Intrinsic quantum efficiency and electro-thermal model of a superconducting nanowire single-photon detector

• Published in: Journal of modern optics 2009-01, Vol.56 (2-3), p.345-351
• Main Authors: Semenov, Alexei, Haas, Philipp, Hübers, Heinz-Wilhelm, Ilin, Konstantin, Siegel, Michael, Kirste, Alexander, Drung, Dietemar, Schurig, Thomas, Engel, Andreas
• Format: Article
• Language: English
• Subjects: Atoms & subatomic particles; electro-thermal normal domain; Exact sciences and technology; Fundamental areas of phenomenology (including applications); General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; nanowire single-photon detectors; Nanowires; Optics; Physics; quantum efficiency; Quantum optics; Quantum theory; Sensors; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; SQUID readout; Superconductors; Thin films
• ISSN: 0950-0340; 1362-3044
• DOI: 10.1080/09500340802578589

Superconducting single-photon detectors from thin niobium nitride nanostrips exhibit a cut-off of the wavelength-independent quantum efficiency along with a moderate energy resolution in the near-infrared spectral range. Before the cut-off, the intrinsic quantum efficiency of the detector reaches ≈30% of the ultimate value, which is physically limited to the absorbance of the detector structure. The intrinsic quantum efficiency is most likely controlled by non-homogeneities of the niobium nitride films. We have developed an electro-thermal model of the detector response that allowed us to optimize the SQUID-based readout and to achieve, in the temperature range from 1 to 6 K, the photon count rate 3 × 10 7 s −1 and a dark count rate less than 10 −4 s −1 .