Open AccessHollow waveguide-miniaturized quantum cascade laser heterodyne spectro-radiometer
Author(s) -
Iain Robinson,
Helen Butcher,
Neil A. Macleod,
Damien Weidmann
Publication year - 2021
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.415371
Subject(s) - quantum cascade laser , optics , materials science , heterodyne (poetry) , radiometer , laser , optoelectronics , transmittance , cascade , physics , chemistry , chromatography , acoustics
A miniature thermal infrared laser heterodyne spectro-radiometer based on hybrid optical integration is demonstrated. A quantum cascade laser emitting at 953 cm -1 (10.5 μm) is used as the local oscillator. Integration is achieved using hollow waveguides inscribed in a copper substrate, with slot-encapsulated optical components positioned to maintain fundamental hybrid mode coupling. The demonstrator performances are studied in the laboratory and show a noise level within 1.6 times of the ideal case. Atmospheric high-resolution transmittance spectroscopy of carbon dioxide and water vapor in solar occultation is demonstrated. The total column concentrations are derived as well as measurement uncertainties, 399.5 ± 2.2 ppm for CO 2 and 1066 ± 62 ppm for H 2 O. The miniature laser heterodyne spectro-radiometer demonstration opens the prospect for nanosatellite-based high spectral resolution thermal infrared atmospheric sounding.