Design and performance of dual-polarization lumped-element kinetic inductance detectors for millimeter-wave polarimetry

H. McCarrick, G. Jones, B. R. Johnson, M. H. Abitbol, P. A.R. Ade, S. Bryan, P. Day, T. Essinger-Hileman, D. Flanigan, H. G. Leduc, M. Limon, Philip Mauskopf, A. Miller, C. Tucker

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


Aims. Lumped-element kinetic inductance detectors (LEKIDs) are an attractive technology for millimeter-wave observations that require large arrays of extremely low-noise detectors. We designed, fabricated and characterized 64-element (128 LEKID) arrays of horn-coupled, dual-polarization LEKIDs optimized for ground-based CMB polarimetry. Our devices are sensitive to two orthogonal polarizations in a single spectral band centered on 150 GHz with Δν/ν = 0.2. The 65 × 65 mm square arrays are designed to be tiled into the focal plane of an optical system. We demonstrate the viability of these dual-polarization LEKIDs with laboratory measurements. Methods. The LEKID modules are tested with an FPGA-based readout system in a sub-kelvin cryostat that uses a two-stage adiabatic demagnetization refrigerator. The devices are characterized using a blackbody and a millimeter-wave source. The polarization properties are measured with a cryogenic stepped half-wave plate. We measure the resonator parameters and the detector sensitivity, noise spectrum, dynamic range, and polarization response. Results. The resonators have internal quality factors approaching 1 × 106. The detectors have uniform response between orthogonal polarizations and a large dynamic range. The detectors are photon-noise limited above 1 pW of absorbed power. The noise-equivalent temperatures under a 3.4 K blackbody load are <100 μK √s. The polarization fractions of detectors sensitive to orthogonal polarizations are >80%. The entire array is multiplexed on a single readout line, demonstrating a multiplexing factor of 128. The array and readout meet the requirements for 4 arrays to be read out simultaneously for a multiplexing factor of 512. Conclusions. This laboratory study demonstrates the first dual-polarization LEKID array optimized specifically for CMB polarimetry and shows the readiness of the detectors for on-sky observations.

Original languageEnglish (US)
Article numberA45
JournalAstronomy and Astrophysics
StatePublished - Feb 1 2018


  • Cosmic background radiation
  • Instrumentation: detectors
  • Instrumentation: polarimeters

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Design and performance of dual-polarization lumped-element kinetic inductance detectors for millimeter-wave polarimetry'. Together they form a unique fingerprint.

Cite this