Theory of Waves (TDO)

Example of diffuse (left) and localized (right) modes in a correlated disordered medium

Speckle pattern in a strongly scattering medium generated numerically

Disordered hyperuniform pattern of points. When dressed with material scatterers, this ensemble has remarkable optical properties (transparency, absorption, localisation).

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Rémi CARMINATI

Tel.: +33 (0)1 80 96 30 72

Marcel FILOCHE

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Arthur GOETSCHY

Tel.: +33 (0)1 80 96 39 46

Agnès MAUREL

Pierre MILLIEN

Tel.: +33 (0)1 80 96 30 51

Romain PIERRAT

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Characterization and Exploitation of the Rotational Memory Effect in Multimode Fibers Gutiérrez-Cuevas R., , Goetschy A., Bromberg Y., Pelc G., Ravn Andresen E., Bigot L., Quiquempois Y, Bsaibes M, Sillard P., Bigot M., Katz O., De Rosny J., and Popoff S. M. Physical Review X 14, no. 3, 031046 (2024) Abstract: In an ideal perfectly straight multimode fiber with a circular core, the symmetry ensures that rotating the input wave front leads to a corresponding rotation of the output wave front. This invariant property, known as the rotational memory effect (RME), remains independent of the typically unknown output profile. The RME thus offers significant potential for imaging and telecommunication applications. However, in real-life fibers, this effect is degraded by intrinsic imperfections and external perturbations, and is challenging to observe because of its acute sensitivity to misalignments and aberrations in the optical setup. Building on a previously established method for precisely estimating fiber transmission properties, we demonstrate an accurate extraction of RME properties. Additionally, we introduce a comprehensive theoretical framework for both qualitative and quantitative analysis, which specifically links the angular-dependent correlation of the RME to the core deformation’s geometrical properties and the fiber’s mode characteristics. Our theoretical predictions align well with experimental data and simulations for various amounts of fiber distorsion. Finally, we demonstrate the ability to engineer wave fronts with significantly enhanced correlation across all rotation angles. This work enables accurate characterization of distributed disorder from the fabrication process and facilitates calibration-free imaging in multimode fibers. Keywords: multimode fiber; wavefront shaping; correlation; memory effect; imaging; telecommunications
Recovering particle velocity and size distributions in ejecta with photon Doppler velocimetry Don Jayamanne, J. A., R. Outerovitch, F. Ballanger, J. Bénier, E. Blanco, C. Chauvin, P. Hereil, J. Tailleur, O. Durand, R. Pierrat, R. Carminati, A. Hervouët, P. Gandeboeuf, and J. R. Burie Journal of Applied Physics 136, no. 8 (2024) Abstract: When a solid metal is struck, its free surface can eject fast and fine particles. Despite the many diagnostics that have been implemented to measure the mass, size, velocity, or temperature of ejecta, these efforts provide only a partial picture of this phenomenon. Ejecta characterization, especially in constrained geometries, is an inherently ill-posed problem. In this context, Photon Doppler Velocimetry (PDV) has been a valuable diagnostic, measuring reliably particles and free surface velocities in the single scattering regime. Here, we present ejecta experiments in gas and how, in this context, PDV allows one to retrieve additional information on the ejecta, i.e., information on the particles’ size. We explain what governs ejecta transport in gas and how it can be simulated. To account for the multiple scattering of light in these ejecta, we use the Radiative Transfer Equation (RTE) that quantitatively describes PDV spectrograms, and their dependence not only on the velocity but also on the size distribution of the ejecta. We remind how spectrograms can be simulated by solving numerically this RTE and we show how to do so on hydrodynamic ejecta simulation results. Finally, we use this complex machinery in different ejecta transport scenarios to simulate the corresponding spectrograms. Comparing these to experimental results, we iteratively constrain the ejecta description at an unprecedented level. This work demonstrates our ability to recover particle size information from what is initially a velocity diagnostic, but more importantly it shows how, using existing simulation of ejecta, we capture through simulation the complexity of experimental spectrograms.
Perfect active absorption of water waves in a channel by a dipole source Euvé, L. P., K. Pham, P. Petitjeans, V. Pagneux, and A. Maurel Journal of Fluid Mechanics 990 (2024) Abstract: This study investigates the potential use of an active device to efficiently absorb water waves propagating in a channel. The active device comprises a dipole source consisting of two sources in quasi-opposition of phase. We explore the feasibility of this approach to achieve perfect absorption of guided waves through interference phenomena. To accomplish this, we establish the law governing the waves emitted by the dipole source to optimize the absorption of specific incident waves. The validity of this law is demonstrated through numerical simulations and laboratory experiments, encompassing both the harmonic and transient regimes of the experimental set-up.
Anderson mobility edge as a percolation transition Filoche, M., P. Pelletier, D. Delande, and S. Mayboroda Physical Review B 109, no. 22 (2024) Abstract: The location of the mobility edge is a long-standing problem in Anderson localization. In this Letter, we show that the effective confining potential introduced in the localization landscape (LL) theory predicts the onset of delocalization in 3D tight-binding models in a large part of the energy-disorder diagram. Near the edge of the spectrum, the eigenstates are confined inside the basins of the LL-based potential. The delocalization transition corresponds to the progressive merging of these basins, resulting in the percolation of this classically allowed region throughout the system. This approach, shown to be valid both in the cases of uniform and binary disorders despite their very different phase diagrams, allows us to reinterpret the Anderson transition in the tight-binding model: the mobility edge appears to be composed of two parts, one being understood as a percolation transition.

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Presentation of the thematics

Our theoretical activities (modeling, analytical and statistical approaches, numerical simulations) aim to understand the properties of waves (optical, acoustic, electronic) in their interactions with matter and their propagation. These activities cover three major themes: the study of inherently complex systems (biological tissues, disordered semiconductors, multimode fibers, chaotic cavities, networks); the control of material complexity (correlated disorder, local resonances, time-dependent media); and wave control (spatial, spectral for classical waves, state nature for quantum waves).

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Active collaborations

Habib Ammari, Department of Mathematics, ETH Zurich
Geoffroy Aubry, Institut de Physique de Nice
Jean-Philippe Banon, Laboratoire Charles Fabry, Institut d’Optique Graduate School
Élie Bretin, Pôle de Mathématiques, INSA Lyon
Yaron Bromberg, Complex Photonics Lab, The Hebrew University of Jerusalem
CEA DAM
Hui Cao, Hui Cao Research Laboratory, Yale University
Nicolas Cherroret, Complex Quantum Systems, Laboratoire Kastler Brossel
Hilton de Aguiar, Optical imaging in biological and complex media, Laboratoire Kastler Brossel
Aristide Dogariu, Photonics Diagnostics of Random Media, University of Central Florida
Sylvain Gigan, Optical imaging in biological and complex media, Laboratoire Kastler Brossel
Wade Hsu, Optics in Complex Systems, USC
Ori Katz, Advanced Imaging Lab, The Hebrew University of Jerusalem
Fabrice Mortessagne, Institut de Physique de Nice
Sushil Mujumdar Nano-Optics & Mesoscopic Optics Laboratory, TIFR

Vincent Pagneux, LAUM, Le Mans
Philippe Petitjeans, PMMH, ESPCI Paris - PSL
Kim Pham, LMI, ENSTA Paris
Stefan Rotter, Nonlinear dynamics & Complex scattering, Vienna University of Technology
L’Oréal
Saint-Gobain Recherche
Riccardo Sapienza, Complex Nanophotonics, King’s College London
Frank Scheffold, Soft Matter Photonics, University of Fribourg
John Schotland, Department of Mathematics, Yale University
Laurent Seppecher, École Centrale de Lyon
Boris Shapiro, Technion
Simons collaboration on Localization of Waves
Ingve Simonsen, NTNU, Trondheim
Douglas Stone, Department of Applied Physics, Yale University
Nicolas Treps, Quantum Optics group, Laboratoire Kastler Brossel
Damien Vandembroucq, PMMH, ESPCI Paris - PSL
Silvia Vignolini, Max Planck Institute of colloids and interfaces, Potsdam
Kevin Vynck, Institut Lumière Matière, Lyon
Alexey Yamilov, METIS group, MST
Hasan Yılmaz, Bilkent University

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Theory of Waves (TDO)

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