Bidaux, YvesBismuto, AlfredoPatimisco, PietroSampaolo, AngeloGresch, TobiasStrubi, GregoryBlaser, StéphaneTittel, Frank K.Spagnolo, VincenzoMuller, AntoineFaist, Jérôme2016-11-222016-11-222016Bidaux, Yves, Bismuto, Alfredo, Patimisco, Pietro, et al.. "Mid infrared quantum cascade laser operating in pure amplitude modulation for background-free trace gas spectroscopy." <i>Optics Express,</i> 24, no. 23 (2016) Optical Society of America: 26464-26471. http://dx.doi.org/10.1364/OE.24.026464.https://hdl.handle.net/1911/92712We present a single mode multi-section quantum cascade laser source composed of three different sections: master oscillator, gain and phase section. Non-uniform pumping of the QCL’s gain reveals that the various laser sections are strongly coupled. Simulations of the electronic and optical properties of the laser (based on the density matrix and scattering matrix formalisms, respectively) were performed and a good agreement with measurements is obtained. In particular, a pure modulation of the laser output power can be achieved. This capability of the device is applied in tunable-laser spectroscopy of N2O where background-free quartz enhanced photo acoustic spectral scans with nearly perfect Voigt line shapes for the selected absorption line are obtained.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttp://dx.doi.org/10.1364/OE.24.026464