Photonic engineering of infrared surface waves
P.I.: Thomas Antoni
Infrared spectrum is a very exciting playground that offers promising applications for environmental monitoring or energy sobriety. First, most of usual molecules, such as pollutants or toxic substances, exhibit on optical resonance between 3 µm and 14 µm. Second, an important part of micro-electronic devices power consumption is waisted due to heating whose typical temperatures correspond to a radiation in this same range. Still, photonic handling of infrared waves is a recent consideration since no coherent sources where available before the late 2000’s and the development of quantum cascade lasers or thermal antennas. We developed an expertise in far field observation of infrared surface waves combining Fourier Transform InfraRed (FTIR) measurements and Finite Difference Time Domain (FDTD) simulations.
We achieve the measurement of infrared near field upon corrugated surfaces with a microscopic resolution using a Michelson interferometer (FTIR) coupled to a microscope that operates both in the visible and in the infrared.
Samples design and prediction of measurements is performed using Finite Difference in TimeDomain based on the open-source Meep software developed by MIT.
Demonstration of broadband thermal wave coherence
Coherent emission of thermal radiation due to surface waves has been demonstrated in the early 2000’s due to the coupling of light to phonons forming the so called surface phonon polariton. However, this phenomenon being resonant, coherent emission only existed on an extremely narrow part of the infrared spectrum (see grey regions on the Fig. centre and right). We showed that, on sub-micron layers (Fig. left), surface wave could form even far from the polaritonic resonance with coherence length of several hundreds of microns.
Cavity resonator integrated grating filter for quantum cascade lasers
In order to identify a variety of different species the emission wavelength of quantum cascade lasers needs to be tuned on a large spectrum. Such a tuning cannot be performed at the level of source since the wavelength is directly determined by its geometrical parameters. A solution is to embed the active region in an external cavity one of the mirror of which is spectrally selective (Fig. left). Selective reflection can be obtained using cavity resonator integrated grating filters (CRIGFs) such as presented on figure middle, that consists in a surface waves cavity formed by two Distributed Bragg Reflectors (DBR) coupled to far field radiation with a Grating Coupler (GC). We demonstrated that such photonic systems can exhibit reflectivities about 50% (which is enough to engender lasing effect) over 100 cm-1 in the 2000 cm-1 region as can be seen on the Fig. right.
Continuously tunable cavity resonator integrated grating filter for quantum cascade lasers
Based on the proof of principle of the broadband selectivity of quantum cascade lasers emission with cavity resonator integrated grating filters we are investigating new structures that would enable continuous tuning of the sources.
Localization of thermally generated surface waves in microcavities
Thermally generated surface waves being proved to have large coherence lengths on submicrons layers, we are investigating the opportunity to use photonic engineering to manipulate their propagation and turn this unwanted heating into an exploitable electromagnetic signal. This project is part of Flaghship project (Manipulating Heat Carriers: from the Classical to the Quantum Regime), hence supported by a public grant overseen by the French National Research Agency (ANR) as part of the “Investissements d’Avenir” program (Labex NanoSaclay, reference: ANR-10-LABX-0035).
EM2C (CentraleSupélec, Univ. Paris-Saclay, France), Institut Fresnel (Marseille, France) LAAS (Toulouse, France), MirSense (Palaiseau, France), C2N (Univ. Paris-Saclay, Orsay, France).
S. Gluchko, B. Palpant, S. Volz, R. Braive and T. Antoni, Thermal excitation of broadband and long-range surface waves on SiO2 submicron films, Applied Physics Letters, 110 (26) :263108, 2017. DOI: 10.1063/1.4989830
S. Augé, S. Gluchko, A.L. Fehrembach, E. Popov, T. Antoni, S. Pelloquin, A. Arnoult, A. Monmayrant, and O. Gauthier-Lafaye, Mid-infrared cavity resonator integrated grating filters, Optics Express, 26 (21) :27014–27020, 2018. DOI: 10.1364/OE.26.027014
S. Augé, S. Gluchko, A.L. Fehrembach, E. Popov, T. Antoni, S. Pelloquin, A. Arnoult, G. Maisons, A. Monmayrant, and O. Gauthier-Lafaye, Extended cavity quantum cascade laser with cavity resonator integrated grating filters, Optics Express, 28 (4) :4801–4809, 2020. DOI: 10.1364/OE.385740
Anomalous thermal conductivity by surface phonon-polaritons of polar nano thin films due to their asymmetric surrounding media, J. Ordonez-Miranda, L. Tranchant, T. Tokunaga, B. Kim, B. Palpant, Y. Chalopin, T. Antoni, and S. Volz, J. Appl. Phys. 112, 084311 (2013). DOI: 10.1063/1.4793498