Characterization of a tantalum-aluminum-based kinetic inductance detector for far-infrared space applications

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,) J Junhua Chen (School of Pharmacy) R Rui Tan (Academy of Interdisciplinary Studies on Intelligent Molecules, Tianjin Key Laboratory of Structure and Performance for Functional Molecules, College of Chemistry) 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 M Mei Yu J Jian Chen P Peiheng Wu

Abstract

Future far-infrared space observatories equipped with cryogenic telescopes require ultra-sensitive detectors to enable measurements limited only by the sky background. We present the design, fabrication, and characterization of a superconducting kinetic inductance detector (KID) at 4.3 THz. The lumped-element KID comprises a tantalum interdigitated capacitor and a 100-nm-wide aluminum-line inductor connected in parallel. The inductor acts also as a low-volume absorber. We achieved photon-noise-limited performance with a noise equivalent power of 1.9 × 10−19 W/Hz referenced to absorbed blackbody power at a modulation frequency of 300 Hz. Under optical loading above 1.83 fW, the detector remains stable with white-noise spectra extending down to ∼100 mHz.

Article Details

Volume / Issue Vol. 127, Issue 16
Published October 20, 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,

J

Junhua Chen

School of Pharmacy

R

Rui Tan

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

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

M

Mei Yu

J

Jian Chen

P

Peiheng Wu