Open AccessBowtie loaded meander antenna for a high-temperature superconducting terahertz detector and its characterization by the Josephson effect
Author(s) -
Mei Yu,
Haifeng Geng,
Shoulu Jiang,
Tao Hua,
D. Y. An,
Wei Xu,
Zhi Ning Chen,
Jun Li,
Huabing Wang,
Jian Chen,
Peiheng Wu
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.390997
Subject(s) - terahertz radiation , responsivity , josephson effect , antenna (radio) , noise equivalent power , detector , optics , optoelectronics , materials science , superconductivity , physics , electrical engineering , condensed matter physics , engineering
In a quasi-optical system, the high temperature superconducting terahertz detector often suffers from a fundamental problem of low coupling efficiency with the terahertz signal, especially for the detector based on YBa 2 Cu 3 O 7-δ (YBCO) bicrystal Josephson junction (JJ) due to a small normal-state resistance. Here, we developed a bowtie loaded meander antenna to enhance coupling efficiency. Differing from the conventional characterization confining on vector network analyzers, we applied three methods to evaluate the antenna, including the measurements of the maximal size of the first order Shapiro step under per incident power, the coupling efficiency between the antenna and the junction, and voltage responsivity. Furthermore, with simulation analysis, we propose that the inductive reactance of the YBCO bicrystal JJ is around 60 ohms under terahertz irradiation at 210 GHz, thus, the reactance is comparable as that of the antenna.