A dual-polarization mid-infrared kinetic inductance detector with photon-noise-limited performance

R Runfeng Su (Research Institute of Superconductor Electronics, School of Electronic Science and Engineering & National Key Laboratory of Microwave Photonics (Nanjing University), Nanjing University 1 , Nanjing 210023,) R Rui Tan (Academy of Interdisciplinary Studies on Intelligent Molecules, Tianjin Key Laboratory of Structure and Performance for Functional Molecules, College of Chemistry) J Junhua Chen (School of Pharmacy) Y Yuwei Zhu (Research Institute of Superconductor Electronics, School of Electronic Science and Engineering & National Key Laboratory of Microwave Photonics (Nanjing University), Nanjing University 1 , Nanjing 210023,) T Tianyuan Chi (Research Institute of Superconductor Electronics, School of Electronic Science and Engineering & National Key Laboratory of Microwave Photonics (Nanjing University), Nanjing University 1 , Nanjing 210023,) S Siming Zang (Research Institute of Superconductor Electronics, School of Electronic Science and Engineering & National Key Laboratory of Microwave Photonics (Nanjing University), Nanjing University 1 , Nanjing 210023,) J Jingbo Wu X Xuecou Tu K Kai Zheng J Jian Chen P Peiheng Wu

Abstract

The mid-infrared (MIR) regime carries rich information about planetary-atmosphere biosignatures and galaxy evolution while providing higher star-planet contrast ratios than the optical band. Advanced detectors employing diverse technologies are under development to enable MIR observations across ground-based, balloon-borne, and space platforms. We demonstrate the design, fabrication, and characterization of a superconducting dual-polarization kinetic inductance detector (KID) operating around 20 μm. The MIR KID is a lumped-element device comprising a tantalum interdigitated capacitor connected in parallel with an aluminum inductor. The inductor, which simultaneously functions as an absorber, captures signals in two orthogonal linear polarizations. In a photon-flux-integrated mode, the detector achieves photon-noise-limited performance for absorbed powers ≳1 fW, with a limiting noise equivalent power of 2.9 × 10−18 W/Hz at 300 Hz.

Article Details

Volume / Issue Vol. 127, Issue 19
Published November 10, 2025
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (11)

R

Runfeng Su

Research Institute of Superconductor Electronics, School of Electronic Science and Engineering & National Key Laboratory of Microwave Photonics (Nanjing University), Nanjing University 1 , Nanjing 210023,

R

Rui Tan

Academy of Interdisciplinary Studies on Intelligent Molecules, Tianjin Key Laboratory of Structure and Performance for Functional Molecules, College of Chemistry

J

Junhua Chen

School of Pharmacy

Y

Yuwei Zhu

Research Institute of Superconductor Electronics, School of Electronic Science and Engineering & National Key Laboratory of Microwave Photonics (Nanjing University), Nanjing University 1 , Nanjing 210023,

T

Tianyuan Chi

Research Institute of Superconductor Electronics, School of Electronic Science and Engineering & National Key Laboratory of Microwave Photonics (Nanjing University), Nanjing University 1 , Nanjing 210023,

S

Siming Zang

Research Institute of Superconductor Electronics, School of Electronic Science and Engineering & National Key Laboratory of Microwave Photonics (Nanjing University), Nanjing University 1 , Nanjing 210023,

J

Jingbo Wu

X

Xuecou Tu

K

Kai Zheng

J

Jian Chen

P

Peiheng Wu