Light in Complex Nanostructures

The Light in Complex Nanostructures (acronym COS) group studies the properties of coherent systems involving multiple and strong scattering of light with individual or ensemble of quantum or classical nano-objects or both. We tackle the problem starting from the elementary level (individual nanoresonators), to the microsystem level (nanoresonators possibly dressed by quantum emitters, small nanoresonator assemblies), towards the mesoscopic scale (metasurfaces).

OPEN POSITIONS

The group would be delighted to successfully support the application of a young researcher for a junior (Chargé de Recherche) CNRS position in January 2025.

The group received significant grants in 2023 and is presently offering several postdoc positions:

Within the interdisciplinary ERC project UNSEEN (2.2 M€), we study disordered metasurfaces to synthesize new visual effects. We try to understand how to design the structures to control their far field appearance attributes, such as specular and diffuse colors, glossiness, transparency, iridescence… We offer several postdocs positions on electromagnetic model of disordered systems, BSDF characterization, rendering, nanofabrication with top-down and bottom-up approaches. More details on the topic can be found in Nature Mater. 21, 1035–41 (2022) and ACS Nano 17, 6362–72 (2023). Talented PhD students are also welcome.
In collaboration with ST-Microelectronics (Grenoble), we offer a 3-year postdoctoral position on numerical electromagnetic techniques and software for analysing large optical metasurfaces with plenty metaatoms. The postdoctoral researcher will develop a freeware based on a method called global polarizability matrix (JOSA A 37,70-83 (2020)) and will validate the numerical simulations by comparing them with real experimental data collected by our partners at ST-Edinburgh.
For the ANR project WHEEL on Non-Hermitian physics and quasinormal modes, we are offering a 2-year postdoc position on a topic of the properties of light in time-varying nanoresonators. For an illustrative example of our work, see our freeware published in Computer Physics Communications 284, 108627 in 2023.

CURRENT MEMBERS

Philippe LALANNE (CNRS Research Director, philippe.lalanne@institutoptique.fr, google scholar, middle)
Miao CHEN (CSC Post-doctoral fellow, google scholar, right, June 2022-24)
Tong WU (Post-doctoral fellow, google scholar, rightmost, Mai 2024 - Dec. 2025)
Yuhao XU (Post-doctoral fellow, not on the picture, March 2024 - Feb. 2027)
Roman Calpe (PhD student, Joensuu Univ.)

ASSOCIATE MEMBERS

Loïc TRAN (PhD student, collaboration L'Oréal, Paris)

ALUMNI

Benjamin ROUSSEAUX (Post-doctoral fellow, leftmost on the picture)
Adrian AGREDA (Post-doctoral fellow, now at ELORPrint Tec)
Marie-Caroline SOLIGNAC (PhD student, collaboration SVI - Saint Gobain Recherche)
Denis ARRIVAULT (CNRS Research Engineer, now at INRIA-Bordeaux)
Maxime BERTRAND (PhD student, now at SharpEye, Paris)
Armel PITELET (Post-doctoral fellow)
Kevin VYNCK (CNRS Research Scientist, now at Institut Lumière Matière, Lyon, France)
Louis BELLANDO (Post-doctoral fellow, now at LOMA, Talence, France)
Kévin COGNEE (PhD student, now at City University of New York, USA)
Rémi FAGGIANI (PhD student, now at Greenerwave, Paris, France)
Alexandre GRAS (PhD student)
Wei YAN (Post-doctoral fellow, now at Westlake University, Hangzhou, China)
Jianji YANG (Post-doctoral fellow, now at Facebook, California, USA)
Xiaorun ZANG (PhD student, now at Tampere University of Technology, Finland)

FREEWARES

The group has launched 4 freeware packages: MAN, RETOP,RETICOLO and RETICOLOfilm-stack. The graph shows the download statistics of the first three freewares since January 2020.

MAN (Modal Analysis of Nanoresonators)

MAN is an open-source software for analyzing electromagnetic resonators. It relies on two solvers, QNMEig and QNMPole, which compute and normalize the quasinormal modes (QNMs). QNMEig operates under the COMSOL Multiphysics platform; QNMPole can be used with any frequency-domain electromagnetic solver. These solvers are valued by an increasing number of toolboxes, which allow a transparent analysis of nanoresonators with analytical formulae: field reconstruction in the modal basis, scattering cross-section spectra, LDOS maps, Purcell factor, multipolar decomposition, generation of second-harmonics, temporal domain analysis …

Interested users are encouraged to read a publication in Computer Physics Communications and lesson a userguide video or an introduction video to the software.

Download MAN V8.3 from ZENODO

RETOP

RETOP is an open-source Matlab toobox that implements a near-to-far-field transformation for computing radiation diagrams. This transformation is implemented in many electromagnetic software, however for most of them, like COMSOL multiphysics, the transformation is restricted to object in free space. RETOP operates for objects in stratified media. It can be used to compute the radiation diagram in the superstrate and the substrate. The substrate may support guided modes or surface plasmon modes with metal layers. RETOP additionally computes the in-plane radiation diagram in the guided modes.

To compute both radiation diagrams, RETOP just needs to know the near-field computed on a rectangular box that contains the object. This computation can be performed with any full-wave Maxwell solver, including COMSOL. Special attention is made to the interface with COMSOL Multiphysics.

Download RETOP V9 from ZENODO

RETICOLO

RETICOLO implements the rigorous coupled wave analysis (RCWA) for 1D (classical and conical diffraction) and 2D crossed gratings. It operates under a MATLAB environment and incorporates an efficient and accurate toolbox for visualizing the electromagnetic field in the grating. As a spinoff, version V9 launched in 2021 incorporates a toolbox to analyze thin film stacks made of uniform media with arbitrary anisotropy.

Download RETICOLO V9 from Zenodo

RETICOLOfilm-stack

RETICOLOfilm-stack is the latest freeware launched in 2024. It is written in MATLAB. It computes the reflection and transmission of arbitrary stacks of anisotropic thin films in a vectorialized manner for multi wavelengths and incidences. It further allows you to compute the modes, e.g. surface polaritons, waveguide modes, of the stack.

Download RETICOLOfilm-stack from Zenodo

LINKS TO SEMINARS

RECENT TEXTBOOK PUBLICATIONS

The textbook Introduction to Nanophotonics (Oxford Univ. Press 2022) illustrates the theoretical foundations of nanophotonics, as well as the major advances in the field based on artificial metallic and dielectric nanostructures. The material is aimed at graduate students with a background in physics and electrical engineering. Quite uniquely, it presents a comprehensive overview of modes, be them of guided, Bloch or quasinormal types, a concept that aroses many subfields of nanophotonics, from photonic and plasmonic waveguides, to photonic crystals, microcavities and nanoantennas.

Introduction to Nanophotonics is more than a treatise on photons ans electrons being lost on tiny islands or in a jungle of nano-structured materials; the authors discuss numerous useful configurations while ensuring the reader does not lose sight of te underlying principles, includind an unprecedentedly clear description of the role of plasmons." Dieter Pohl, University of Basel

You can obtain a PDF version that closely resembles the final production, although the pagination may vary.

BIOGRAPHY Philippe Lalanne

Philippe Lalanne is a CNRS Research Director. He is an international expert in computational and nanoscale electrodynamics. He was first involved in the group of Pierre Chavel at l'Institut d’Optique at Orsay. In 1995, he spent a sabbatical year with G.M. Morris at the Institute of Optics in Rochester.

With his colleagues, he has developped new modal theories and launched new numerical tools for analysing nanostructured surfaces [JOSAA96], photonic-crystal waveguides [JOSAA01,OExpress07] and nanoresonators [LPR18,PRB18]. He has used these developments to provide deep insight into the physical mechanisms involved in key nanoscale optical phenomena and devices, e.g. the confinement of light in photonic-crystal cavities [Nature04,LPR08], the extraordinary optical transmission [Nature08,Nature12], and the light interaction with localized plasmons [PRL13,ACSPhoton21]. He has designed and demonstrated novel nanostructures with record or completely novel performance in their time, e.g. photonic-crystal cavities with tapered mirrors, slow light injectors, directional plasmon launchers, broadband single-channel photon sources. He has pionnered the field of metasurfaces in the 90's, showing the first metalenses with large numerical aperture and large efficiencies (>80%) [JOSAA99,LPR17], with designs that are basically the same as those used nowadays.

He has supervised 17 PhD candidates and co-supervised 6 PhD candidates. He is a member of the editorial board of Laser & Photonics Reviews. He is a recipient of the Bronze medal of CNRS, the prix Fabry de Gramont of the Société Française d’Optique, and an Advanced ERC grant in 2023 (UNSEEN project). He is a fellow of the IOP, OPTICA and SPIE.