Waves in complex systems

Waves in complex systems


The group Waves in complex systems is interested in controlling the classical wave transport properties in various systems whose mastered designs range from homogeneous systems with complex geometries to either periodic or disordered structured materials. Thanks to experimental versatile platforms in optics and microwaves, and with a strong expertise in numerical simulations in wave chaos theory, the group investigates various themes : mixed dynamics in multimode optical fibers, electromagnetic chaotic reverberation chambers, superfluidity and condensation of light, analog approaches of topological effects in condensed matter, wave diffusion or localization. While the undertaken studies are motivated by the incentive of addressing fundamental questions, they still give rise to numerous applicative developments.

This website is under construction, more info will be added soon...


Academic staff

Matthieu Bellec, CNRS researcher

Valérie Doya, Assistant Professor at UNS

Ulrich Kuhl, Professor at UNS, head of the team

Olivier Legrand, Professor at UNS

Claire Michel, Assistant Professor at UNS

Fabrice Mortessagne, Professor at UNS


Aurélien Eloy

Philip Del Hougne

PhD students

Omar Boughdad

Khalid Oubaha



If you want more info about the following research lines, please get in touch with the contact persons.

Chaotic electromagnetic reverberation chambers

Electromagnetic reverberation chambers are now commonly used in the domain of ElectroMagnetic Compatibility where electronic devices or wireless objects are tested for immunity. By changing the geometry of current reverberation chambers (RC) to make them chaotic, we have shown that the statistical requirements of well operating RCs are better satisfied in the more complex geometry due to spatial and spectral statistical behaviors being very close to Random Matrix Theory predictions. More specifically, we have shown that in the low-frequency range of RCs, non-generic modes could be suppressed by drastically reducing the amount of parallel walls. Among other results we demonstrate that, in a chaotic cavity, the low-frequency limit of well operating RCs can be reduced under the usual values met in conventional mode-stirred RCs.


Femtosecond laser inscription of complex photonics structures

When an ultrashort laser is tightly focused inside transparent material, its optical properties (e.g. the refractive index) are permanently modified in the bulk at the nano/microscale. We developed this technique to inscribe complex photonics structures in various supports. Among others, we fabricate photonic lattices in glasses and nonlinear crystals to investigate the properties of light in discrete systems from the very quantum regime (photon pairs) to the extreme nonlinear regime (laser filamentation).

Contact — 

Fluids of light

When light propagates in a nonlinear medium, it may behave as a quantum fluid. Thanks to a versatile optical setup, based on a photorefractive nonlinear crystal, we aim at studying experimentally various aspects of quantum hydrodynamics ranging from superfluidity to quantized vortices and wave condensation in complex landscapes.

Contact — 

Multimode optical fibers

Multimode optical fibers are commonly used as sensors, for imaging systems and are also at the heart of current investigations in telecommunications, to enhance capacity of transmission. Our activities are dedicated to the study and exploitation of the singular spatial properties of the optical field in multimode fibers. These features are induced by a modification of the shape of the transverse cross section of the fibers and lead to wave chaos. Complex wave properties, such as uniform distribution or spatial localization for propagation modes are either exploited in telecommunication devices (e.g. to enhance pump absorption in double clad fiber amplifier) or studied for their consequence on the dynamics of thermalization in presence of perturbative nonlinearity. 

Contact — Valérie Doya

Topological photonics

Topological insulators are materials that are electronically insulating in the bulk and perfectly conducting at the surface. The wave nature of their topological properties allows to bring it to the photonics realm with many targeted applications on robust light transport. Using microwave resonators or optical waveguide arrays, we aim at investigating the topological properties of photons in lattices in both static and Floquet regimes.

Contact — , ,

Jobs & Internships

PhD and postdoc positions

Currently no open positions are available. However, we regularly propose PhD thesis at the doctoral school of the Université Côte d'Azur, if you're interested in applying, please contact us to know the application modalities.


We regularly offer internship position (Master (graduated) or Licence (undergraduates) degrees). If you are interested in joining us, please feel free to contact one of us.



  • Anisotropic nonlinear refractive index measurement of a photorefractive crystal via spatial self-phase modulation
    O. Boughdad, A. Eloy, F. Mortessagne, M. Bellec, C. Michel
    arXiv:1907.09865 (2019)

Journal Articles


  • Broadband integrated beam splitter using spatial adiabatic passage
    T. Lunghi, F. Doutre, A. P. Rambu, M. Bellec, M. P. De Micheli, A. M. Apetrei, O. Alibart, N. Belabas, S. Tascu, S. Tanzilli
    Opt. Exp. 26, 27058 (2018)arXiv:1810.06262


  • Partial chiral symmetry-breaking as a route to spectrally isolated topological defect states in two-dimensional artificial materials
    C. Poli, H. Schomerus, M. Bellec, U. Kuhl, F. Mortessagne
    2D Mater. 4, 025008 (2017)arXiv:1512.02284
  • Fluctuations in an established transmission in the presence of a complex environment
    D. V. Savin, M. Richter, U. Kuhl, O. Legrand, and F. Mortessagne
    Phys. Rev. E 96, 032221 (2017) 
  • Energy Localization Effects Within a Reverberation Chamber and Their Reduction in Chaotic Geometries
    K. Selemani, E. Richalot, O. Legrand, O. Picon and F. Mortessagne
    IEEE Trans. Electromagn. Compat59, 325 (2017)


  • Energy landscape in a Penrose tiling
    P. Vignolo, M. Bellec, J. Boehm, A. Camara, J.-M. Gambaudo, U. Kuhl, F. Mortessagne
    Phys. Rev. B 93075141 (2016)arXiv:1411.1234
  • Decoupled polarization dynamics of incoherent waves and bimodal spectral incoherent solitons
    A. Fusaro, J. Garnier, C. Michel, G. Xu, J. Fatome, L. Wright, F. Wise, A. Picozzi 

    Optics Letters 41, 3992 (2016)
  • Regular modes in a mixed-dynamics-based optical fiber
    C. Michel, M. Allgaier, V. Doya
    Phys. Rev. E 93, 022201 (2016)
  • Decoupled polarization dynamics of incoherent waves and bimodal spectral incoherent solitons
    A. Fusaro, J. Garnier, C. Michel, G. Xu, J. Fatome, L. Wright, F. Wise, A. Picozzi
    Opt. Lett. 41, 3992 (2016)
  • Lossy chaotic electromagnetic reverberation chambers: Universal statistical behavior of the vectorial field
    J.-B. Gros, U. Kuhl, O. Legrand, and F. Mortessagne
    Phys. Rev. E 93, 032108  (2016)


  • Microwave experiments simulating quantum search and directed transport in artificial graphene
    J. Boehm, M. Bellec, F. Mortessagne, U. Kuhl, S. Barkhofen, S. Gehler, H.-J. Stoeckmann, I. Foulger, S. Gnutzman and G. Tanner
    Phys. Rev. Lett. 114, 110501 (2015)arXiv:1409.2382
  • Turbulent dynamics of an incoherently pumped passive optical fiber cavity : Quasisolitons, dispersive waves, and extreme events
    M. Conforti, A. Mussot, J. Fatome, A. Picozzi, S. Pitois, C. Finot, M. Haelterman, B. Kibler, C. Michel, G. Millot
    Phys. Rev. A 91, 023823 (2015)


  • Selective enhancement of topologically induced interface states in a dielectric resonator chain
    C. Poli, M. Bellec, U. Kuhl, F. Mortessagne and H. Schomerus
    Nature Commun. 6, 6710 (2015)arXiv:1407.3703
  • Experimental width shift distribution: A test of nonorthogonality for local and global perturbations
    J.-B. Gros, U. Kuhl, O. Legrand, F. Mortessagne, E. Richalot, and D. V. Savin
    Phys. Rev. Lett. 113, 224101 (2014)
  • Universal behaviour of a wave chaos based electromagnetic reverberation chamber
    J.-B. Gros, O. Legrand, F. Mortessagne, E. Richalot, and K. Selemani
    Wave Motion 51, 664 (2014)




  • Statistics of resonance states in a weakly open chaotic cavity with continuously distributed losses
    C. Poli , O. Legrand, and F. Mortessagne
    Phys. Rev. E, 82, 055201 (R) (2010)


  • Gain-controlled wave chaos in a chaotic optical fibre
    C. Michel, S. Tascu, V. Doya, O. Legrand, F. Mortessagne
    J. Eur. Opt. Soc. 4, 09020 (2009)
  • Controlled excitation of scar modes in passive and active multimode chaotic fiber
    C. Michel, V. Doya, S. Tascu, W. Blanc, O. Legrand, and F. Mortessagne
    Appl. Opt. 48, 163 (2009)
  • Approximate equivalence between guided modes in a low-contrast photonic bandgap fiber and stationary Maxwell TM modes of a high-contrast 2D photonic structure
    O. Legrand, L. Labonte, and C. Vanneste
    Applied Optics 48, 1047 (2009)
  • Wave chaos techniques to analyze a modeled reverberation chamber
    G. Orjubin, E. Richalot, O. Picon, and O. Legrand
    Comptes Rendus Physique 10, 42 (2009)
  • Quasimodes of a chaotic elastic cavity with increasing local losses
    O. Xeridat, C. Poli, O. Legrand, F. Mortessagne, and P. Sebbah
    Phys. Rev. E 80, 035201(R) (2009)
  • Avoided-level-crossing statistics in open chaotic billiards
    C. Poli, B. Dietz , O. Legrand, F. Mortessagne and A. Richter
    Phys. Rev. E80, 035204(R) (2009)
  • Statistics of resonance states in open chaotic systems: A perturbative approach
    C. Poli, D. V. Savin, O. Legrand, and F. Mortessagne
    Phys. Rev. E 80, 046203 (2009)



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