Nano-optics and devices
The activities of the Nano-optics and Devices team encompass theoretical and experimental studies of fundamental mechanisms in Nanophotonics. The objective is to assess their potential to realize original optical and optoelectronic devices. The team is mainly working on two different topics.
Parity-Time (PT) symmetry
We study the properties of PT-symmetric systems in integrated optics. The goal is to evaluate the potential of these peculiar properties to implement devices such as lasers, switches, filters, from science to products. This work is done in close collaboration with Anatole Lupu at C2N.
The word metasurface is a shortcut to refer to a surface that has been functionalized with nano-objects and whose optical properties can be engineered with a great flexibility by a careful choice of the nanostructures. Metasurfaces are becoming more and more important in the Nanophotonics toolbox, either to create passive devices such as diffractive optical elements (DOEs) or active devices such as lasers or yet other light sources. They are often built from an ensemble of resonant nanoantennas, periodic or not, and active devices rely on the use of colloidal quantum dots, phase-change materials or doped semiconductors. We have identified two key issues.
Accurate, fast and physically meaningful models of light scattering by a metasurface are needed to understand, to design, and to optimize devices. We are currently developing such theoretical/numerical tools based on a modal formalism. We calculate the optical properties of a whole metasurface from the sole knowledge of the modes of each individual constituent. Part of this work is done in the framework of the ANR project Resonance (2017-2020).
The optical properties of active metasurfaces are driven by the complex interplay between multiple scattering of photons inside the structure and condensed-matter effects. We investigate the optical properties of an ensemble of heavily-doped nanocrystals as a function of its arrangement (dense or dilute, ordered or disordered) by confronting experimental measurements and numerical simulations. One objective is to determine to what extent a dense arrangement of the nanocrystals affects their physical properties (electron scattering rate, carrier mobility…) and thus their optical response.