title: Mid-infrared surface transmitting and detecting quantum cascade device for gas-sensing.
abstract: We present a bi-functional surface emitting and surface detecting mid-infrared device applicable for gas-sensing. A distributed feedback ring quantum cascade laser is monolithically integrated with a detector structured from a bi-functional material for same frequency lasing and detection. The emitted single mode radiation is collimated, back reflected by a flat mirror and detected by the detector element of the sensor. The surface operation mode combined with the low divergence emission of the ring quantum cascade laser enables for long analyte interaction regions spatially separated from the sample surface. The device enables for sensing of gaseous analytes which requires a relatively long interaction region. Our design is suitable for 2D array integration with multiple emission and detection frequencies. Proof of principle measurements with isobutane (2-methylpropane) and propane as gaseous analytes were conducted. Detectable concentration values of 0-70% for propane and 0-90% for isobutane were reached at a laser operation wavelength of 6.5 μm utilizing a 10 cm gas cell in double pass configuration.
authors.affiliation: Institute of Solid State Electronics, TU-Wien, Floragasse 7, 1040 Wien, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Harrer
authors.affiliation: Institute of Solid State Electronics, TU-Wien, Floragasse 7, 1040 Wien, Austria.
authors.forename: Rolf
authors.initials: R
authors.lastname: Szedlak
authors.affiliation: Institute of Solid State Electronics, TU-Wien, Floragasse 7, 1040 Wien, Austria.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Schwarz
authors.affiliation: Institute of Chemical Technologies and Analytics Division Environmental and Process Analytics, TU-Wien, Getreidemarkt 9/164 AC, 1060 Wien, Austria.
authors.forename: Harald
authors.initials: H
authors.lastname: Moser
authors.affiliation: Center for Micro- and Nanostructures, TU-Wien, Floragasse 7, 1040 Wien, Austria.
authors.forename: Tobias
authors.initials: T
authors.lastname: Zederbauer
authors.affiliation: Institute of Solid State Electronics, TU-Wien, Floragasse 7, 1040 Wien, Austria.
authors.forename: Donald
authors.initials: D
authors.lastname: MacFarland
authors.affiliation: Austrian Academy of Sciences, Dr. Ignaz Seipel-Platz 2, 1010 Wien, Austria.
authors.forename: Hermann
authors.initials: H
authors.lastname: Detz
authors.affiliation: Institute of Solid State Electronics, TU-Wien, Floragasse 7, 1040 Wien, Austria.
authors.forename: Aaron Maxwell
authors.initials: AM
authors.lastname: Andrews
authors.affiliation: Center for Micro- and Nanostructures, TU-Wien, Floragasse 7, 1040 Wien, Austria.
authors.forename: Werner
authors.initials: W
authors.lastname: Schrenk
authors.affiliation: Institute of Chemical Technologies and Analytics Division Environmental and Process Analytics, TU-Wien, Getreidemarkt 9/164 AC, 1060 Wien, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Lendl
authors.affiliation: Institute of Solid State Electronics, TU-Wien, Floragasse 7, 1040 Wien, Austria.|Center for Micro- and Nanostructures, TU-Wien, Floragasse 7, 1040 Wien, Austria.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Strasser