Presentation + Paper
31 August 2022 5.3 THz MgB2 hot electron bolometer mixer operated at 20 K
Author Affiliations +
Abstract
Heterodyne receivers combining a NbN HEB mixer with a local oscillator (LO) are the work horse for high resolution ( ≥106 ) spectroscopic observations at supra-terahertz frequencies. We report an MgB2 HEB mixer working at 5.3 THz with 20 K operation temperature based on a previously published paper [Y. Gan et al, Appl. Phys. Lett., 119, 202601 (2021)]. The HEB consists of a 7 nm thick MgB2 submicron-bridge contacted with a spiral antenna. It has a Tc of 38.4 K. By using hot/cold blackbody loads and a Mylar beam splitter all in vacuum, and applying a 5.25 THz FIR gas laser as the LO, we measured a minimal DSB receiver noise temperature of 3960 K. The latter gives a DSB mixer noise temperature of 1470 K. This sensitivity is 28 times better than a room temperature Schottky mixer at 4.7 THz, but about 2.5 times less sensitive than an NbN HEB mixer. The latter must be operated around 4 K. The IF noise bandwidth is about 10 GHz, which is 2.5-3 times larger than an NbN HEB. With further optimization, such MgB2 HEBs are expected to reach a better sensitivity. That the low noise, wide IF bandwidth MgB2 HEB mixers can be operated in a compact, low dissipation 20 K Stirling cooler can significantly reduce the cost and complexity of heterodyne instruments and therefore facilitate new space missions.
Conference Presentation
© (2022) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
J. R. Gao, Y. Gan, B. Mirzaei, J. R.G. Silva, and S. Cherednichenko "5.3 THz MgB2 hot electron bolometer mixer operated at 20 K", Proc. SPIE 12190, Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XI, 121900F (31 August 2022); https://doi.org/10.1117/12.2630161
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KEYWORDS
Terahertz radiation

Receivers

Antennas

Bridges

Superconductors

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