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LALANNE Philippe


The Light in Complex Nanostructures 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 nanoparticles), to the nanosystem level (nanoparticles possibly dressed by quantum resonators, small nanoparticle assemblies), towards the macroscopic scale (complex ensembles composed of hundreds of nanoparticles interacting with micron-scale systems).

We regularly have postdoc, PhD and master positions to offer, and welcome applications of candidates who would be interested in working with us. Please contact us directly by email ( &


On the dune, from left to right:

  • Philippe LALANNE (Directeur de Recherche, group leader,
  • Wei YAN (Post-doc --> permanent position at Westlake Institute, China)
  • Louis BELLANDO (Post-doc --> postdoc with LOMA)
  • Maxime BERTRAND (PhD)
  • Alexandre GRAS (PhD)
  • Kevin VYNCK (Chargé de Recherche, permanent researcher)
  • Kévin COGNEE (PhD, not on the picture, co-supervised by Femius Koenderink)
  • Tong WU (Post-doc, not on the picture)


The group is offering a 1-year postdoc position and a PhD position for january.

2019 postdoc position QNM (PDF / 70,75 kB)
2019_postdoc_LP2N_modeling_BSDF (PDF / 369,58 kB)
2019_PhD_LP2N_characterization (PDF / 364,71 kB)


  • Kevin Vynck is recipient of the Bronze medal of CNRS in 2018
  • Kévin Cognée received the poster prize awards at the 2018 EOSAM conference in Delft
  • The group is going to welcome a third CNRS permanent specialized in computational science in 2019.


MAN: MAN stands for Modal Analysis of Nanoresonator. It computes and normalizes the resonance modes (often called quasinormal modes, QNMs) of photonic-crystal resonators, plasmonic nanoresonators, or hybrids. It additionally reconstructs the scattered field with the modal basis. There are two versions, QNMEig and QNMPole.

QNMEig has been launched in 2018 and relies on COMSOL Multiphysics. It encompasses a QNM eigensolver and a pedagogical Matlab toolbox (under construction) dedicated to the reconstruction of the scattered field in the QNM basis.

The QNM solver that can be thought as an extension of the existing COMSOL modal solver that additionally normalizes the QNMs and handles resonators made with dispersive media, e.g. metals. The QNMs are computed by solving a quadratic polynomial eigenproblem derived from Maxwell's equations. Thus a large number of modes (set by the user) are computed with a “single” computation without preconditioning. This makes the solver more effective than QNMPole, our QNM eigensolver developed in 2013 to compute QNMs one by one. We recommend the use of QNMeig in general.

2019 QNMEig V6a (ZIP / 13,57 MB)
QNMPole has been launched in 2013. It is an open Matlab source code for computing a few resonance-modes of almost arbitrary micro/nanoresonators.

QNMPole calculates and normalizes the modes of plasmonic or photonic micro/nanoresonators. The computation requires an initial guess value for each pole. It relies on a pedagogical Matlab toolbox that can be used to calculate the modal absorption/extinction cross-sections or the Purcell factor. The toolbox can be used with any frequency-domain Maxwell’s equations solvers; For COMSOL Multiphysics, we additionally provide the Matlab programs that operate under Matlab-COMSOL livelink. The use of QNMPole is recommended if one just needs to compute a few modes to analyse some resonator properties, or if the permittivity of some constitutive materials does not follow a N-pole Lorentz-Drude model (required for QNMEig).

QNMPole V7 (ZIP / 3,47 MB)
You may also download the slides of a 2H course on QNMs and a 40 mn conference
2018 QNM course (PDF / 7,57 MB)
2019 MetaNano St pertersbourg (PDF / 3,49 MB)

RETOP: RETOPT performs near-to-far-field transformations for free and guided waves in thin-film stacks. It is composed of a set of Matlab programs

RETOP implements a near-to-far-field transformation for light scattering or emission problems in stratified media. RETOP can be used to retrieve the free-space and/or guided-mode radiation diagrams. The transformation uses the near-field (computed on a rectangular box with any full-wave Maxwell’s solver, not provided). It is especially relevant for calculating the scattering of nanoparticle on substrates. Special attention is made to the interface with COMSOL Multiphysics.

NtoFField package V8 (ZIP / 5,14 MB)

RETICOLO: Rigorous Coupled Wave Analysis for gratings with Matlab interface.

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.



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

With his colleagues, he has launched modal theories and numerical tools for gratings [JOSAA 13 (1996)], photonic-crystal waveguides [JOSAA 18 (2001), OE 15 (2007)] and nanoresonators [PRL 110 (2013), PRB 97 (2018)]. He has used these tools to provide deep insight into the physical mechanisms involved in key nanoscale optical phenomena and devices, e.g. light confinement in photonic-crystal cavities [APL 78 (2001), Nature 429 (2004)] and the extraordinary optical transmission [Nature 452 (2008) & 492 (2012)]. He has designed and demonstrated novel nanostructures with record performance in their time, e.g. slow light injectors [Opt. Lett. 32 (2007)], directional plasmon couplers [PRL 95 (2005), NanoLett 11 (2011)], broadband single-channel photon sources [PRL 105 (2010), Nat Photon. (2010)]. Noteworthy, he has pioneered the development of metalenses [Opt. Lett. 23 (1998), JOSAA 16 (1999), Laser&Photonics reviews 11 (2017)] by arraying nanopillar waveguides that impart a local phase shift as a function of their dimension. This allowed the demonstration of the first flat diffractive optical element with high efficiency and large-NA.

He has co-authored about 190 publications in peer-reviewed journals and filled 10 patents. He is a recipient of the Bronze medal of CNRS and the prix Fabry de Gramont of the Société Française d’Optique.

He is an associate editor of OPTICA, a member of the editorial board of Laser & Photonics Reviews, and is director of GDR ondes, a broad virtual laboratory that gathers the French community working on acoustic and electromagnetic waves, He is a fellow of the IOP, OSA and SPIE and was Carl Zeiss visiting Professor at Jena in 2010.

He was the supervisor of 17 PhD candidates, has co-supervised 6 PhD candidates. He is currently working on computational electrodynamics, nanophotonics, and complex optical nanostructures


Master 1: optical waveguides
  1. Chapter 1: Macroscopic Maxwell’s equations
  2. Chapter 2: Introduction to optical waveguide modes
  3. Chapter 3: Classical waveguide geometries
  4. Chapter 4: Theory of optical waveguides
  5. Chapter 5: Pulse propagation in waveguides
Master 2: Optical artificial materials
  1. Outline
  2. Introduction (slides)
  3. Chapter 1 Bloch modes
  4. Chapter 2 Equivalence between subwavelength gratings and homogeneous thin films
  5. Chapter 3 Metamaterials & metasurfaces
  6. Chapter 6 Plasmonics


Metalenses: an historical perspective responding to the report published in Science 352, June 2016, by the Harvard group, "Metalenses at visible wavelengths: diffraction-limited focusing and subwavelength resolution imaging"

Slow waves: a comparison between photonic and plasmonic modes.
2019 acsphotonics perspective on slow plasmons & photons