4.7-THz Local Oscillator for the GREAT Heterodyne Spectrometer on SOFIA

Author

Richter, Heiko ; Wienold, Martin ; Schrottke, Lutz ; Biermann, Klaus ; Grahn, Holger T. ; Hubers, Heinz-Wilhelm

Author_Institution

Inst. of Opt. Sensor Syst., German Aerosp. Center (DLR), Berlin, Germany

Volume

5

Issue

4

fYear

2015

fDate

Jul-15

Firstpage

539

Lastpage

545

Abstract

The design and the performance of a 4.7-THz local oscillator (LO) for the GREAT (German REceiver for Astronomy at Terahertz frequencies) heterodyne spectrometer on SOFIA, the Stratospheric Observatory for Infrared Astronomy, are presented. The LO is based on a quantum-cascade laser, which is mounted in a compact mechanical cryocooler. The LO provides up to 150 μW output power into a nearly Gaussian shaped beam. It covers the frequency range from approximately +2 to -4 GHz around the fine structure line of neutral atomic oxygen, OI, at 4.7448 THz. The LO has been successfully operated on SOFIA during six observation flights in May 2014 and January 2015.

Keywords

heterodyne detection; infrared spectroscopy; oscillators; quantum cascade lasers; terahertz spectroscopy; GREAT heterodyne spectrometer; SOFIA; Stratospheric Observatory for Infrared Astronomy; compact mechanical cryocooler; frequency 4.7 THz; local oscillator; nearly Gaussian shaped beam; neutral atomic oxygen; quantum-cascade laser; Absorption; Frequency measurement; Heat sinks; Instruments; Mixers; Quantum cascade lasers; Temperature measurement; Heterodyne spectroscopy; SOFIA; local oscillator (LO); quantum-cascade laser (QCL); terahertz (THz);

fLanguage

English

Journal_Title

Terahertz Science and Technology, IEEE Transactions on

Publisher

ieee

ISSN

2156-342X

Type

jour

DOI

10.1109/TTHZ.2015.2442155

Filename

7152992