Physical Review X (Oct 2024)

A 25-micrometer Single-Photon-Sensitive Kinetic Inductance Detector

  • Peter K. Day,
  • Nicholas F. Cothard,
  • Christopher Albert,
  • Logan Foote,
  • Elijah Kane,
  • Byeong H. Eom,
  • Ritoban Basu Thakur,
  • Reinier M. J. Janssen,
  • Andrew Beyer,
  • Pierre M. Echternach,
  • Sven van Berkel,
  • Steven Hailey-Dunsheath,
  • Thomas R. Stevenson,
  • Shahab Dabironezare,
  • Jochem J. A. Baselmans,
  • Jason Glenn,
  • C. Matt Bradford,
  • Henry G. Leduc

DOI
https://doi.org/10.1103/PhysRevX.14.041005
Journal volume & issue
Vol. 14, no. 4
p. 041005

Abstract

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We report measurements characterizing the performance of a kinetic inductance detector array designed for a wavelength of 25 microns and very low optical background level suitable for applications such as a far-infrared instrument on a cryogenically cooled space telescope. In a pulse-counting mode of operation at low optical flux, the detectors can resolve individual 25-micron photons. In an integrating mode, the detectors remain photon noise limited over more than 6 orders of magnitude in absorbed power from 70 zW to 200 fW, with a limiting noise equivalent power of 4.6×10^{−20} W Hz^{−1} at 1 Hz. In addition, the detectors are highly stable with flat power spectra under optical load down to 1 mHz. Operational parameters of the detector are determined including the efficiency of conversion of the incident optical power into quasiparticles in the aluminum absorbing element and the quasiparticle self-recombination constant.