Next seminar : Séminaire du LPTMS: Arthur Goetschy

Tuesday, September 25 2018 at 11:00:00

Optimizing energy transfer and dwell times in disordered systems: a statistical approach

Arthur Goetschy (Institut Langevin, ESPCI)

When a wave such as light propagates through a disordered system, it is scattered many times in various directions before escaping. At first sight, this process is well described by diffusion. However, diffusion neglects interferences, making us believe that the information content of a wave is progressively lost through spreading. This picture is incorrect. In fact, multiple scattering is a linear process that redistributes information among many degrees of freedom which can nowadays be resolved and manipulated. In this talk, we will give an overview of different strategies to achieve original light transport properties in open disordered systems that deviate both from the diffusive picture and the Gaussian field model. First, we will characterize the statistical properties of the transmission matrix to demonstrate large energy transfer or focusing through nominally opaque media [1, 2]. Then, we will discuss how to achieve similar performance in transmission by means of the reflection matrix only [3, 4]. Finally, we will characterize the distribution of scattering times, in order to generate excitations with particularly short or long dwell times. References:
  • [1] A. Goetschy and A. D. Stone, Filtering Random Matrices: The Effect of Incomplete Channel Control in Multiple Scattering, Phys. Rev. Lett. 111, 063901 (2013)
  • [2] C. W. Hsu, S. F. Liew, A. Goetschy, H. Cao, and A. D. Stone, Correlation-enhanced control of wave focusing in disordered media, Nature Phys. 13, 497 (2017)
  • [3] N. Fayard, A. Goetschy, R. Pierrat and R. Carminati, Mutual Information between Reflected and Transmitted Speckle Images, Phys. Rev. Lett. 120, 073901 (2018)
  • [4] I. Starshynov, A. M. Paniagua-Diaz, N. Fayard, A. Goetschy, R. Pierrat, R. Carminati and J. Bertolotti, Non-Gaussian Correlations between Reflected and Transmitted Intensity Patterns Emerging from Opaque Disordered Media, Phys. Rev. X 8, 021041 (2018)

Last Highlight : C’est chaud une ville la nuit

Il tend à faire plus chaud en centre-ville qu’en banlieue, mais certains centres chauffent davantage que d’autres. Une équipe de recherche internationale vient d’établir que la disposition des immeubles conditionne la température nocturne des villes – une découverte clé pour l’urbanisme de demain.

Voir la suite de l'article sur  CNRS - le journal

Ref. : J. M. Sobstyl, T. Emig, M. J. Abdolhosseini Qomi, F.-J. Ulm et R. J.-M. Pellenq, Role of City Texture in Urban Heat Islands at Nighttime, Phys. Rev. Lett. 120, 108701 (2018)

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