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

Source: [Design and performance of dual-polarization lumped-element kinetic inductance detectors for millimeter-wave polarimetry](<https://www.sota2.com/research/paper/68fa374d1e209131ce8b0f96>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-24T22:18:49.006Z

Authors: 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, P. Mauskopf, A. Miller, C. Tucker

Published: 2017-10-05T23:56:19.000Z

## Abstract

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 $\\Delta\\nu/\\nu=0.2$. The $65\\times 65$ 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. 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. The resonators have internal quality factors approaching $1\\times 10^{6}$. 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 $\<100~\\mu\\mathrm{K\\sqrt{s}}$. 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. This laboratory study demonstrates the first dual-polarization LEKID array optimized for CMB polarimetry and shows the readiness of the detectors for on-sky observations.

## Recorded benchmark results

A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage.

## Original sources and implementation

[Original paper](<https://arxiv.org/abs/1710.02239>)

[PDF](<https://arxiv.org/pdf/1710.02239.pdf>)