DocumentCode :
836069
Title :
Characterization of an STJ-based direct detector of submillimeter waves
Author :
Ariyoshi, Seiichiro ; Matsuo, Hiroshi ; Otani, Chiko ; Sato, Hiromi ; Shimizu, Hirohiko M. ; Kawase, Kodo ; Noguchi, Takashi
Author_Institution :
Inst. of Phys. & Chem. Res., Saitama, Japan
Volume :
15
Issue :
2
fYear :
2005
fDate :
6/1/2005 12:00:00 AM
Firstpage :
920
Lastpage :
923
Abstract :
We have developed submillimeter-wave direct detectors employing niobium-based superconducting tunnel junctions (STJs), with broadband spectral response, high sensitivity and imaging capability. Spectral response peaked at 650 GHz with a fractional bandwidth of 14 percent, which fits one of the important atmospheric windows for an astronomical project. We also confirmed the linearity of the detector response in the dynamic range greater than 106. The measured coupling efficiency was about 0.2, which was lower than the expected value of 0.5. The measured noise current of the detector was 10 fA/√Hz, which agreed with the shot noise from the residual leakage current of 100 pA at 0.3 K. Resultant noise equivalent power (NEP) is 1.6×10-16 W/√Hz, that is less than the background photon fluctuation limit for ground-based submillimeter-wave observations.
Keywords :
niobium; spectral analysis; submillimetre wave detectors; superconducting junction devices; superconductive tunnelling; 0.3 K; 100 pA; 650 GHz; Nb; background photon fluctuation limit; broadband spectral response; direct detectors; leakage current; niobium; submillimeter waves detector; superconducting tunnel junctions; Atmospheric measurements; Atmospheric waves; Background noise; Bandwidth; Detectors; Dynamic range; Extraterrestrial measurements; Josephson junctions; Linearity; Superconducting device noise; Direct detectors; Josephson junctions; niobium; submillimeter wave detectors;
fLanguage :
English
Journal_Title :
Applied Superconductivity, IEEE Transactions on
Publisher :
ieee
ISSN :
1051-8223
Type :
jour
DOI :
10.1109/TASC.2005.850119
Filename :
1439789
Link To Document :
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