Photon noise from chaotic and coherent millimeter-wave sources measured with horn-coupled, aluminum lumped-element kinetic inductance detectors
astro-ph.IM
/ Authors
Daniel Flanigan, Heather McCarrick, Glenn Jones, Bradley R. Johnson, Maximilian H. Abitbol, Peter Ade, Derek Araujo, Kristi Bradford, Robin Cantor, George Che
and 11 more authors
Peter K. Day, Simon Doyle, Carl Bjorn Kjellstrand, Henry G LeDuc, Michele Limon, Vy Luu, Philip Mauskopf, Amber Miller, Tony Mroczkowski, Carole Tucker, Jonas Zmuidzinas
/ Abstract
We report photon-noise limited performance of horn-coupled, aluminum lumped-element kinetic inductance detectors at millimeter wavelengths. The detectors are illuminated by a millimeter-wave source that uses an active multiplier chain to produce radiation between 140 and 160 GHz. We feed the multiplier with either amplified broadband noise or a continuous-wave tone from a microwave signal generator. We demonstrate that the detector response over a 40 dB range of source power is well-described by a simple model that considers the number of quasiparticles. The detector noise-equivalent power (NEP) is dominated by photon noise when the absorbed power is greater than approximately 1 pW, which corresponds to $\mathrm{NEP} \approx 2 \times 10^{-17} \, \mathrm{W} \, \mathrm{Hz}^{-1/2}$, referenced to absorbed power. At higher source power levels we observe the relationships between noise and power expected from the photon statistics of the source signal: $\mathrm{NEP} \propto P$ for broadband (chaotic) illumination and $\mathrm{NEP} \propto P^{1/2}$ for continuous-wave (coherent) illumination.