PAILLARD , Vincent

Near-and far-field optical properties of silicon nanostructures under linear polarization (Gaussian beam), and azimuthally or radially focused cylindrical vector beams are investigated by finite-difference time-domain method (FDTD) in Meep open-source software. A python toolkit allowing FDTD simulations in Meep for using those excitation...

In this article, we propose a concise theoretical framework based on mixed-field susceptibilities to describe the decay of magnetic dipoles induced by nonmagnetic nanostructures. This approach is first illustrated in simple cases in which analytical expressions of the decay rate can be obtained. We then show that a more refined numerical...

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We investigate second harmonic generation from individual silicon nanowires and study the influence of resonant optical modes on the far field nonlinear emission. We find that the polarization of the second harmonic has a size-dependent behavior and explain this phenomenon by considering different surface and bulk nonlinear susceptibility...

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2D networks of Si and Ag nanocrystals have been fabricated in the same SiO2 matrix by Ultra-Low-Energy Ion-Beam-Synthesis. Our synthesis scheme differs from a simple sequential ion implantation and its key point is the control of the matrix integrity through an appropriate intermediate thermal annealing. Si nanocrystal layer is synthesised...

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We design planar silicon antennas for controlling the emission rate of magnetic or electric dipolar emitters. Evolutionary algorithms coupled to the Green Dyadic Method lead to different optimized geometries which depend on the nature and orientation of the dipoles. We discuss the physical origin of the obtained configurations thanks to modal...

The tailoring of optical properties of photonic nanostructures is usually based on a reference design. The target optical behavior is obtained by variations of an initial geometry. This approach however can be of limited versatility, in particular if complex optical properties are desired. In order to design double-resonant photonic...

The rational design of photonic nanostructures consists of anticipating their optical response from systematic variations of simple models. This strategy, however, has limited success when multiple objectives are simultaneously targeted, because it requires demanding computational schemes. To this end, evolutionary algorithms can drive the...

Hydrogen and helium co-implantation is nowadays used to efficiently transfer thin Si layers and fabricate silicon on insulator wafers for the microelectronic industry. The synergy between the two implants which is reflected through the dramatic reduction of the total fluence needed to fracture silicon has been reported to be strongly influenced...

We study second harmonic generation (SHG) from individual silicon nanowires. We show that second harmonic intensity is strongly dependent on the Mie resonances supported by the nanowire. The second harmonic polarization also has a size-dependent behavior, which is linked to different surface and bulk-like nonlinear susceptibility contributions....

We demonstrate inverse design of plasmonic nanoantennas for directional light scattering. Our method is based on a combination of full-field electrodynamical simulations via the Green dyadic method and evolutionary optimization (EO). Without any initial bias, we find that the geometries reproducibly found by EO work on the same principles as...

Improving the brightness of single-photon sources by means of optically resonant nanoantennas is a major stake for the development of efficient nanodevices for quantum communications. We demonstrate that nanoxerography by atomic force microscopy makes possible the fast, robust and repeatable positioning of model quantum nanoemitters...

It has been experimentally demonstrated only recently that a simultaneous excitation of interfering electric and magnetic resonances can lead to uni-directional scattering of visible light in zerodimensional dielectric nanoparticles. We show both theoretically and experimentally, that stronglyanisotropic scattering also occurs in individual...

High refractive index dielectric nanostructures provide original optical properties thanks to the occurrence of size- and shape-dependent optical resonance modes. These modes commonly present a spectral overlap of broad, low-order modes (\textit{e.g}. dipolar modes) and much narrower, higher-order modes. The latter are usually characterized by...

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We demonstrated the high throughput production of ultra-thin SiNWs by the innovative Inductively Coupled Plasma (ICP) approach. Our investigations revealed that the vast majority (∼95%) of the ICP produced SiNWs grew according to the Oxide Assisted Growth mechanism, and the 5% through the Vapor-Liquid-Solid mechanism. These SiNWs present an...

Polarization control using single plasmonic nanoantennas is of interest for subwavelength optical components in nano-optical circuits and metasurfaces. Here, we investigate the role of two mechanisms for polarization conversion by plasmonic antennas: Structural asymmetry and plasmon hybridization through strong coupling. As a model system we...

The presence of a Localized Surface Plasmon Resonance in doped semiconductor nanostructures opens a new field for plasmonics and metasurfaces. Semiconductor nanostructures can be easily processed, have weak dissipation losses, and the plasmon resonance can be tuned from the mid- to the near-infrared spectral range by changing the dopant...

We optimize silicon nano-antennas to enhance and steer the emission of local quantum sources. We combine global evolutionary optimization (EO) with frequency domain electrodynamical simulations, and compare design strategies based on resonant and non-resonant building blocks. Specifically, we investigate the performance of models with different...

Through simulation design, fabrication and characterization of optical sili- con metasurfaces, we discuss the influence of different nanofabrication errors and propose strategies to optimize the robustness of the fabrication of complex metasurfaces.

Abstract Optical metasurfaces have raised immense expectations as cheaper and lighter alternatives to bulk optical components. In recent years, novel components combining multiple optical functions have been proposed pushing further the level of requirement on the manufacturing precision of these objects. In this work, we study in details the...