Missions

Optical nanostructures and dielectric metasurfaces are powerful tools for modulating the properties of light, as they exhibit low optical losses and can support optical resonances. They have been successfully developed to produce structural colors, nonlinear optical responses, and specific spectral responses. Their numerical design and optimization are of paramount importance to achieve the desired optical performance.

Activités

Part 1.
The first objective of this work is to implement inverse design methods to develop dielectric metasurfaces exhibiting precise and specific spectral responses. This inverse approach will be coupled with the numerical methods developed within the research group, including the Fourier Modal Method (FMM), Rigorous Coupled-Wave Analysis (RCWA), and the Finite Element Method (FEM). A numerical code will also be written to establish the correspondence between the reflection or transmission spectra and the color space.

Part 2.
The second objective is to collaborate with the project partners on the fabrication of the designed metasurfaces in the laboratory. The metasurfaces will be fabricated using nanoimprint lithography (NIL).

Part 3.
The third objective is to experimentally characterize the metasurfaces using an optical spectroscopy setup installed at Institut Fresnel. The goal is to evaluate their optical performance and ensure that it matches the expected specifications. Particular emphasis will be placed on spatially resolved optical spectroscopy in order to obtain the spectral responses in transmission and reflection, and to accurately determine the generated color.

Keywords: Metasurfaces, Structural colors, Nanophotonics, Optical spectroscopy

References:
[1] J. Proust, F. Bedu, B. Gallas, I. Ozerov, N. Bonod, “All-Dielectric Colored Metasurfaces with Silicon Mie Resonators,” ACS Nano 10, 7761–7767 (2016).
[2] V. Vashistha, G. Vaidya, A. E. Serebryannikov, N. Bonod, M. Krawczyk, “All-Dielectric Metasurfaces Based on Cross-Shaped Resonators for Color Pixels with Extended Gamut,” ACS Photonics 4, 1076–1082 (2017).
[3] T. Wood, M. Naffouti, J. Berthelot, T. David, J.-B. Claude, L. Métayer, A. Delobbe, L. Favre, A. Ronda, I. Berbezier, N. Bonod, M. Abbarchi, “All-Dielectric Color Filters Based on SiGe Mie Resonator Arrays,” ACS Photonics 4, 873–883 (2017).
[4] S. T. T. Sanghyuk, J. Berthelot, G. Guida, D. Demaille, E. Garcia-Caurel, N. Bonod, B. Gallas, “Circularly Polarized Images with Contrast Reversal Using Pseudo-Chiral Metasurfaces,” ACS Photonics 5, 4068–4073 (2018).

Compétences

The candidate should have a solid background and expertise in nanophotonics, either in the numerical design of metasurfaces or in their experimental characterization. Experience in optical spectroscopy and optical microscopy is expected. Familiarity with Matlab, Python, FORTRAN/C/C++, LaTeX, and other software tools will also be appreciated.

Contexte de travail

Le projet sera mené à l'Institut Fresnel, à Marseille, France (https://www.fresnel.fr/), au sein de l'équipe Clarte. Le groupe Clarte de l'Institut Fresnel possède une expertise reconnue dans le développement de méthodes numériques électromagnétiques ainsi que dans la conception et l'analyse de composants optiques et de nanostructures. Ce projet vise à modéliser, concevoir et analyser des métasurfaces diélectriques présentant des caractéristiques spectrales très spécifiques pour la génération de couleurs structurelles.
L'Institut Fresnel est un laboratoire de recherche affilié à l'université d'Aix-Marseille, au CNRS et à Centrale Méditerranée. Il est situé sur le campus Saint-Jérôme à Marseille. Il regroupe environ 200 personnes.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.