Widely-Tunable Quantum Cascade-Based Sources for the Development of Optical Gas Sensors

Autor: Virginie Zéninari, Raphaël Vallon, Laurent Bizet, Clément Jacquemin, Guillaume Aoust, Grégory Maisons, Mathieu Carras, Bertrand Parvitte
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Sensors, Vol 20, Iss 22, p 6650 (2020)
Druh dokumentu: article
ISSN: 1424-8220
DOI: 10.3390/s20226650
Popis: Spectroscopic techniques based on Distributed FeedBack (DFB) Quantum Cascade Lasers (QCL) provide good results for gas detection in the mid-infrared region in terms of sensibility and selectivity. The main limitation is the QCL relatively low tuning range (~10 cm−1) that prevents from monitoring complex species with broad absorption spectra in the infrared region or performing multi-gas sensing. To obtain a wider tuning range, the first solution presented in this paper consists of the use of a DFB QCL array. Tuning ranges from 1335 to 1387 cm−1 and from 2190 to 2220 cm−1 have been demonstrated. A more common technique that will be presented in a second part is to implement a Fabry–Perot QCL chip in an external-cavity (EC) system so that the laser could be tuned on its whole gain curve. The use of an EC system also allows to perform Intra-Cavity Laser Absorption Spectroscopy, where the gas sample is placed within the laser resonator. Moreover, a technique only using the QCL compliance voltage technique can be used to retrieve the spectrum of the gas inside the cavity, thus no detector outside the cavity is needed. Finally, a specific scheme using an EC coherent QCL array can be developed. All these widely-tunable Quantum Cascade-based sources can be used to demonstrate the development of optical gas sensors.
Databáze: Directory of Open Access Journals
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