TY  - JOUR
AU  - Zhang, W.
AU  - Miao, W.
AU  - Li, S. L.
AU  - Zhou, K. M.
AU  - Shi, S. C.
AU  - Gao, J. R.
AU  - Goltsman, G. N.
PY  - 2013
DA  - 2013//
TI  - Measurement of the spectral response of spiral-antenna coupled superconducting hot electron bolometers
T2  - IEEE Trans. Appl. Supercond.
JO  - IEEE Trans. Appl. Supercond.
SP  - 2300804
VL  - 23
IS  - 3
KW  - NbN HEB detector
AB  - Measured spectral response of spiral-antenna coupled superconducting hot electron bolometers (HEBs) often drops dramatically at frequencies that are still within the frequency range of interest (e.g., ~ 5 THz). This is inconsistent with the implied low receiver noise temperatures from the same measurements. To understand this discrepancy, we exhaustively test and calibrate the thermal sources used in Fourier transform spectrometer measurements. We first investigate the absolute emission spectrum of high-pressure Hg arc lamp, then measure the spectral response of two spiral-antenna coupled NbN HEBs with a Martin-Puplett interferometer as spectrometer and 77 K blackbody as broadband signal source. The measured absolute emission spectrum of Hg arc lamp is proportional to frequency, corresponding to an equivalent blackbody temperature of 4000 K at 1 THz, 1500 K at 3 THz, and 800 K at 5 THz, respectively. Measured spectral response of spiral-antenna coupled NbN HEBs, corrected for air absorption, is nearly flat in the frequency range of 0.5-4 THz, consistent with simulated coupling efficiency between HEB and spiral-antenna. These results explain the discrepancy, and prove that spiral-antenna coupled superconducting NbN HEBs work well in a wide frequency range. In addition, this calibration method and these results are broadly applicable to other quasi-optical THz receivers.
SN  - 1051-8223
UR  - http://ieeexplore.ieee.org/document/6449293/
UR  - https://doi.org/10.1109/TASC.2013.2245173
DO  - 10.1109/TASC.2013.2245173
N1  - exported from refbase (https://db.rplab.ru/refbase/show.php?record=1371), last updated on Thu, 13 May 2021 14:52:19 -0500
ID  - Zhang_etal2013
ER  -