https://doi.org/10.1051/epjconf/202328704011
Over-coupled Helmholtz-like optical resonator for enhanced infrared spectroscopy of molecules
1 DOTA, ONERA, Université Paris Saclay, F-91123 Palaiseau, France
2 Laboratoire Charles Fabry, Institut d’Optique Graduate School, CNRS, Université Paris-Saclay, 91127 Palaiseau, France
3 Centre de Nanosciences et de Nanotechnologies (C2N), CNRS, Université Paris-Saclay, 10 Boulevard Thomas Gobert, 91120 Palaiseau, France
* e-mail: laura.paggi@onera.fr
** e-mail: patrick.bouchon@onera.fr
Published online: 18 October 2023
Electromagnetic Helmholtz resonators are able to strongly and homogeneously enhance an electric field in relatively large volumes, making them attractive for applications to surface enhanced infrared absorption spectroscopy of molecules. We show in this study that such a structure, designed in the over-coupling regime can demonstrate strong enhancement of molecular modes of the polymer poly(methyl methacrylate) and the explosive molecule 2,4-dinitrotoluene over a very wide wavelength range between 5 and 10 µm. Reflectivity contrast provides access to the analyte’s absorption and quantitative information. Helmholtz-like resonators therefore offer a new platform for the creation of sensitive and versatile sensors.
© The Authors, published by EDP Sciences, 2023
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
