Süess, Martin J.
Hundt, P. Morten
Wolf, Johanna M.
- Journal Article
Rights / licenseCreative Commons Attribution 4.0 International
We report on the dynamic behavior of dual-wavelength distributed feedback (DFB) quantum cascade lasers (QCLs) in continuous wave and intermittent continuous wave operation. We investigate inherent etaloning effects based on spectrally resolved light-current-voltage (LIV) characterization and perform time-resolved spectral analysis of thermal chirping during long (>5 µs) current pulses. The theoretical aspects of the observed behavior are discussed using a combination of finite element method simulations and transfer matrix method calculations of dual-section DFB structures. Based on these results, we demonstrate how the internal etaloning can be minimized using anti-reflective (AR) coatings. Finally, the potential and benefits of these devices for high precision trace gas analysis are demonstrated using a laser absorption spectroscopic setup. Thereby, the atmospherically highly relevant compounds CO2 (including its major isotopologues), CO and N2O are simultaneously determined with a precision of 0.16 ppm, 0.22 ppb and 0.26 ppb, respectively, using a 1-s integration time and an optical path-length of 36 m. This creates exciting new opportunities in the development of compact, multi-species trace gas analyzers. Show more
Journal / seriesPhotonics
Pages / Article No.
SubjectQuantum cascade lasers; Multi-wavelength; Laser spectroscopy; Etaloning; Thermal effects; Trace gas analysis
Organisational unit03759 - Faist, Jérôme / Faist, Jérôme
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