Photoluminescence Enhancement of Monolayer WS by n-Doping with an Optically Excited Gold Disk.

In nanophotonics and quantum optics, we aim to control and manipulate light with tailored nanoscale structures. Hybrid systems of nanostructures and atomically thin materials are of interest here, as they offer rich physics and versatility due to the interaction between photons, plasmons, phonons, and excitons. In this study, we explore the optical and electronic properties of a hybrid system, a naturally n-doped monolayer WS covering a gold disk.

Experimental observation of the short-range surface plasmon polariton mode and its longitudinal adiabatic compression in a metallic wedge.

In this study, we explore analytically and experimentally long- and short-range surface plasmon polariton (LR-SPP and SR-SPP, respectively) modes in gold wedges. Especially, we aim to observe the 2-dimensional confinement of the electromagnetic field in gold wedges as it could enhance the light-matter interaction by offering a local density of states which depends on the propagation constant, consequently on the wedge height. The LR-SPP mode can propagate over a long distance, but the real part of the propagation constant remains relatively insensitive to the decreasing wedge height.

Toward Perfect Optical Diffusers: Dielectric Huygens' Metasurfaces with Critical Positional Disorder.

Conventional optical diffusers, such as thick volume scatterers (Rayleigh scattering) or microstructured surface scatterers (geometric scattering), lack the potential for on-chip integration and are thus incompatible with next-generation photonic devices. Dielectric Huygens' metasurfaces, on the other hand, consist of 2D arrangements of resonant dielectric nanoparticles and therefore constitute a promising material platform for ultrathin and highly efficient photonic devices. When the nanoparticles are arranged in a random but statistically specific fashion, diffusers with exceptional properties are expected to come within reach.

Chiral Bilayer All-Dielectric Metasurfaces.

Three-dimensional chiral plasmonic metasurfaces were demonstrated to offer enormous potential for ultrathin circular polarizers and applications in chiral sensing. However, the large absorption losses in the metallic systems generally limit their applicability for high-efficiency devices. In this work, we experimentally and numerically demonstrate three-dimensional chiral dielectric metasurfaces exhibiting multipolar resonances and examine their chiro-optical properties.

Nanostructure-modulated planar high spectral resolution spectro-polarimeter.

We present a planar spectro-polarimeter based on Fabry-Pérot cavities with embedded polarization-sensitive high-index nanostructures. A 7 µm-thick spectro-polarimetric system for 3 spectral bands and 2 linear polarization states is experimentally demonstrated. Furthermore, an optimal design is theoretically proposed, estimating that a system with a bandwidth of 127 nm and a spectral resolution of 1 nm is able to reconstruct the first three Stokes parameters with a signal-to-noise ratio of -13.

Direct and High-Throughput Fabrication of Mie-Resonant Metasurfaces Single-Pulse Laser Interference.

High-index dielectric metasurfaces featuring Mie-type electric and magnetic resonances have been of great interest in a variety of applications such as imaging, sensing, photovoltaics, and others, which led to the necessity of an efficient large-scale fabrication technique. To address this, here we demonstrate the use of single-pulse laser interference for direct patterning of an amorphous silicon film into an array of Mie resonators a few hundred nanometers in diameter. The proposed technique is based on laser-interference-induced dewetting.

Laser-induced spatially-selective tailoring of high-index dielectric metasurfaces.

Optically resonant high-index dielectric metasurfaces featuring Mie-type electric and magnetic resonances are usually fabricated by means of planar technologies, which limit the degrees of freedom in tunability and scalability of the fabricated systems. Therefore, we propose a complimentary post-processing technique based on ultrashort (≤ 10 ps) laser pulses. The process involves thermal effects: crystallization and reshaping, while the heat is localized by a high-precision positioning of the focused laser beam.

Analyzing the polarization response of a chiral metasurface stack by semi-analytic modeling.

We investigate a class of stacked metasurfaces where the interaction between layers is dominated by their respective far-field response. Using a semi-analytic scattering matrix approach, we exploit the Fabry-Perot-type response for different layer distances to show the spectral tunability of the resonant effect. This method presents a faster and more intuitive route to modeling Fabry-Perot-type effects than rigorous numerical simulations.