2007年7月
0.5-THz waveguide SIS mixers with NbN/AlN/NbN technology
SPIE
- ,
- ,
- ,
- 巻
- 6840
- 号
- 開始ページ
- 684013
- 終了ページ
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1117/12.755407
- 出版者・発行元
- SPIE-INT SOC OPTICAL ENGINEERING
Heterodyne mixers based on superconducting SIS (superconductor-insulator-superconductor) tunnel junctions have been demonstrated to be the most sensitive coherent detectors at millimeter and submillimeter wavelengths. In fact, conventional superconducting SIS mixers with Nb/AIO(x)/Nb junction and Nb/SiO2/Nb tuning circuit have shown good performances with the noise temperature reaching as low as three times the quantum limit below 0.7THz, which is the gap frequency of Nb-based SIS junctions. However, due to the large loss in Nb thin-film superconducting microstrip lines, the noise performance of Nb SIS mixers deteriorates significantly above 0.7THz. With a gap frequency double that of Nb-based SIS junctions, NbN-based SIS junctions are of particular interest for the development of heterodyne mixers in the terahertz region.
Considering the bandwidth and output power of local-oscillator (LO) signal sources are quite limited around 1THz, we firstly develop a waveguide NbN-based SIS mixer at 0.5THz. Three types of SIS junctions, i.e., long junction, parallel-connected tunnel junction (PCTJ) and distributed junction array (DJ) are investigated. They are all comprised of NbN-AlN-NbN tri-layer fabricated on an MgO substrate and have the same current density (J(c)) of 10kA/cm(2). In this paper, we describe their design, fabrication and preliminary experimental results.
Considering the bandwidth and output power of local-oscillator (LO) signal sources are quite limited around 1THz, we firstly develop a waveguide NbN-based SIS mixer at 0.5THz. Three types of SIS junctions, i.e., long junction, parallel-connected tunnel junction (PCTJ) and distributed junction array (DJ) are investigated. They are all comprised of NbN-AlN-NbN tri-layer fabricated on an MgO substrate and have the same current density (J(c)) of 10kA/cm(2). In this paper, we describe their design, fabrication and preliminary experimental results.
- リンク情報
- ID情報
-
- DOI : 10.1117/12.755407
- ISSN : 0277-786X
- Web of Science ID : WOS:000254507200031