caa a22 4500 445372621 CHVBK 20180317142952.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s00340-010-4093-8 doi (NATIONALLICENCE)springer-10.1007/s00340-010-4093-8 Non-symmetrical line broadening effects using short-pulse QCL spectrometers as determined with sub-nanosecond time-resolution [Elektronische Daten] [S. Welzel, J. Röpcke] Quantum cascade lasers (QCLs) have attracted considerable interest as an alternative tuneable narrow bandwidth light source in the mid-infrared spectral range for chemical sensing. Pulsed QCL spectrometers are often used with short laser pulses and a bias current ramp similar to diode laser spectroscopy. Artefacts in the recorded spectra such as disturbed line shapes or underestimated absorption coefficients have been reported. A detailed time-resolved high-bandwidth analysis of individual pulses during a laser sweep has been performed. Quantitative results for CH4 absorption features around 1347cm−1 (7.42μm) fell short of the expected values for reasonable operating conditions of the QCL. The origin of the artefacts using short pulses was identified to be partly of the same nature as in the case of long laser pulses. A complex combination with the tuning principle was found, leading to an apparently increased instrumental broadening (effective line width) and underestimated concentrations at low-pressure conditions. The Author(s), 2010 Welzel S. INP Greifswald, Felix-Hausdorff-Str. 2, 17489, Greifswald, Germany aut Röpcke J. INP Greifswald, Felix-Hausdorff-Str. 2, 17489, Greifswald, Germany aut Applied Physics B Springer-Verlag 102/2(2011-02-01), 303-311 0946-2171 102:2<303 2011 102 340 https://doi.org/10.1007/s00340-010-4093-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00340-010-4093-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Welzel S. INP Greifswald, Felix-Hausdorff-Str. 2, 17489, Greifswald, Germany aut NATIONALLICENCE 700 1- Röpcke J. INP Greifswald, Felix-Hausdorff-Str. 2, 17489, Greifswald, Germany aut NATIONALLICENCE 773 0- Applied Physics B Springer-Verlag 102/2(2011-02-01), 303-311 0946-2171 102:2<303 2011 102 340 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer