CC BY
50LS-I-3
OPOs for standoff gas sensing
A. Godard1, G. Walter1, T. Hamoudi1,2, Q. Berthomé1,3, J.B. Dherbecourt1, J.M. Melkonian1, R. Santagata1, M. Raybaut1
1DPHY, ONERA, Université Paris-Saclay, Physics Instrumentation Environment Space Department, Palaiseau, France
2Laboratoire Charles Fabry, Institut d'Optique Graduate School, CNRS, Université Paris-Saclay, Lasers group, Palaiseau, France
3Teem Photonics, Research & Development Department, Meylan, France
Multispecies gas detection, quantification, and localization in the atmosphere has become a growing concern for various applications from environmental and air quality monitoring, to warfare agents detection for defense, through industrial security. For these purposes, laser absorption spectroscopy in the mid-infrared from 1.5 |im to 15 |im is an extremely valuable tool due to the presence of atmospheric transmission windows as well as intense and well separated absorption lines of the species of interest. Depending on the application, the required laser spectral range can be either 1.6-2.2 p,m for spaceborne monitoring of greenhouse gases, 3-5 p,m for hydrocarbons and volatile organic compounds sensing, or 6-14 p,m for hazardous chemicals detection. There is consequently a significant need for broadly tunable laser sources in the mid-infrared exhibiting high spectral purity, narrow linewidth, as well as compactness and robustness for field campaign deployment.
We will present our work on the development of novel optical parametric sources and their integration in gas sensing instruments that have been carried for that purpose. In particular, we have introduced the nested cavity optical parametric oscillator (NesCOPO) scheme that enables to deliver a single frequency tunable emission with a much simpler and more compact device than usual narrow-linewidth OPOs. Its high potential was demonstrated for multiple-gas sensing, either for point measurements or standoff gas detection using lidar instruments [1]. For long range applications, the compact NesCOPO is implemented in a master oscillator power-amplifier (MOPA) architecture [2].
The presentation will especially focus on our latest development on high energy infrared emitters (mJ level) for long range (km) differential absorption LIDAR (DIAL) applications. These developments either address the 1.6 |im - 2.0 |im range for the detection of greenhouse gases (CO2, CH4, and H2O) [3,4], and the 8.0 |im - 12 |im region for the detection of toxic agents [5]. Most of these systems were implemented as transportable optical benches that were deployed for outdoor field test in representative facilities. Emitters' performances, LIDAR instrument capabilities, as well as experimental demonstration results will be discussed during the presentation.
References
[1] Godard, M. Raybaut, M. Lefebvre, Encyclopedia of Analytical Chemistry (2017)
[2] E. Cadiou et al, Opt. Lett. 42, 4044-47 (2017).
[3] E. Cadiou et al, Imaging and Applied Optics 2018, OSA Technical Digest (Optical Society of America, 2018), paper LTu5C.5.
[4] J. Dherbecourt et al, Conference on Lasers and Electro-Optics, OSA Technical Digest (Optical Society of America, 2019), paper ATh3K.1.
[5] J. Armougom et al, Imaging and Applied Optics 2018, OSA Technical Digest (Optical Society of America, 2018), paper LTu5C.6.
