title: Spectroscopy in the gas phase with GaAs/AlGaAs quantum-cascade lasers.
abstract: We demonstrate what we believe is the first application of the recently developed electrically pumped GaAs/AlGaAs quantum-cascade lasers in a spectroscopic gas-sensing system by use of hollow waveguides. Laser light with an emission maximum at 10.009 microm is used to investigate the mid-infrared absorption of ethene at atmospheric pressure. We used a 434-mm-long silver-coated silica hollow waveguide as a sensing element, which served as a gas absorption cell. Different mixtures of helium and ethene with known concentrations are flushed through the waveguide while the laser radiation that passes through the waveguide is analyzed with a Fourier-transform infrared spectrometer. The experimentally obtained discrete ethene spectrum agrees well with the calculated spectrum. A detection threshold of 250 parts per million is achieved with the current setup.
authors: Institute for Solid State Electronics, Technical University of Vienna, Gusshausstrasse 25-29y362, A-1040 Vienna, Austria.
authors: L
authors: L
authors: Hvozdara
authors: S
authors: S
authors: Gianordoli
authors: G
authors: G
authors: Strasser
authors: W
authors: W
authors: Schrenk
authors: K
authors: K
authors: Unterrainer
authors: E
authors: E
authors: Gornik
authors: C S
authors: CS
authors: Murthy
authors: M
authors: M
authors: Kraft
authors: V
authors: V
authors: Pustogow
authors: B
authors: B
authors: Mizaikoff
authors: A
authors: A
authors: Inberg
authors: N
authors: N
authors: Croitoru