@inproceedings{44a76d915304423a88a0575a4edb7eb7,
title = "4×2 HEB receiver at 4.7 THz for GUSTO",
abstract = "GUSTO will be a NASA balloon borne terahertz observatory to be launched from Antarctica in late 2021 for a flight duration of 100-170 days. It aims at reviewing the life cycle of interstellar medium of our galaxy by simultaneously mapping the three brightest interstellar cooling lines: [OI] at 4.7 THz, [CII] at 1.9 THz, and [NII] at 1.4 THz; along the 124 degrees of the galactic plane and through a part of the Large Magellanic Cloud. It will use three arrays of 4x2 mixers based on NbN hot electron bolometers (HEBs), which are currently the most sensitive mixers for high resolution spectroscopic astronomy at these frequencies. Here we report on the design of a novel 4.7 THz receiver for GUSTO. The receiver consists mainly of two subsystems: a 4×2 HEB quasi-optical mixer array and a 4.7 THz multi-beam LO. We describe the mixer array, which is designed as a compact monolithic unit. We show, for example, 10 potential HEB detectors with the state of the art sensitivity of 720 K measured at 2.5 THz. They have a small variation in sensitivity, being less than 3%, while also meet the LO uniformity requirements. For the multi-beam LO we demonstrate the combination of a phase grating and a single QCL at 4.7 THz, which generates 8 sub-LO beams, where the phase grating shows an efficiency of 75%. A preliminary concept for the integrated LO unit, including QCL, phase grating and beam matching optics is presented.",
keywords = "Astronomy, GUSTO, heterodyne, hot electron bolometer, phase grating, quantum cascade laser, terahertz",
author = "Silva, {J. R.G.} and B. Mirzaei and W. Laauwen and N. More and A. Young and C. Kulesa and C. Walker and A. Khalatpour and Q. Hu and C. Groppi and Gao, {J. R.}",
note = "Funding Information: We would like to thank Willem Jellema and Brian Jackson for their help regarding the PILRAP simulations, and Darren Hayton for his advice on the array design. The first author would also like to thank Floris Van der Tak for his support and guidance. This publication has received funding from the European Union{\textquoteright}s Horizon 2020 research and innovation program under grant agreement No 730562 [RadioNet]. Publisher Copyright: {\textcopyright} 2018 SPIE.; Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX 2018 ; Conference date: 12-06-2018 Through 15-06-2018",
year = "2018",
doi = "10.1117/12.2313410",
language = "English (US)",
isbn = "9781510619692",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Jonas Zmuidzinas and Jian-Rong Gao",
booktitle = "Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX",
}