706 research outputs found
Coherent control of Snell's law
We demonstrate coherent control of the generalized Snell's law in ultrathin gradient metasurfaces constructed by an array of V-shaped slot nanoantennas
Cathodoluminescence read-out of the structural phase of gallium nanoparticles
We report on a method of phase identification of gallium nanoparticles via their cathodoluminescence when excited by a scanning electron beam. This feature can be used for high-density phase change memory element
Planar metamaterial with transmission and reflection that depend on the direction of incidence
We report that normal incidence reflection and transmission of circularly polarized electromagnetic waves from and through planar split-ring microwave metamaterials with chiral symmetry breaking depends on the incidence direction and handedness of circular polarization. The effect has a resonant nature and is linked to the lack of mirror symmetry in the metamaterial pattern leading to a polarization-sensitive excitation of electric and magnetic dipolar responses in the meta-molecules. It has striking phenomenological resemblance with the reflective circular dichroism of high-temperature "anyon" superconductors
Noble-metal-free sunlight harvesting meta-surface for water evaporation
We present ultrathin multilayer metamaterial absorbers based on abundant, low-cost materials, to effectively harness solar energy for heating and evaporation of water
Detection, amplification and control of free-electron nearfields
We use SNOM-like optical fiber tips functionalized with plasmonic and metamaterial nanostructures to detect, amplify and control the near-field of free electrons in the spectral range from 450 to 850 THz
Specular nonlinear anisotropic polarization effect along fourfold crystal symmetry axes
We present what is to our knowledge the first experimental observation of the specular nonlinear anisotropic polarization effect of a pump-induced polarization-plane rotation for normal-incidence reflection from the (001) surface of a cubic crystal. In GaAs, azimuth rotation of the order of 9 Ă 10-6 rad is seen for a pump intensity of 75 MW/cm2 at 750 nm, from which the anisotropic component of the cubic nonlinearity |Re(Ïxxxx - 2Ïxxyy - Ïxyyx)| = 5 Ă 10-9 esu is found.<br/
Reconfigurable photonic metamaterials drive by Coulomb, Lorentz and optical forces
Metamaterials offer a huge range of enhanced and novel functionalities that natural materials cannot provide. They promise applications in superresolution imaging, optical data storage, optical filters, polarization control, cloaking, fraud prevention and many more. However, their unique optical properties are often narrowband and usually fixed. Here we demonstrate how the mechanical rearrangement of metamaterial structures at the nanoscale provides a powerful platform for controlling metamaterial properties dynamically. Using thermal, electrical, magnetic and optical control signals we demonstrate large-range tuning, high-contrast switching and modulation of metamaterial optical properties at megahertz frequencies and beyond. Beyond the obvious benefit of adding tunability to known metamaterial functionalities, this unlocks many new opportunities in areas such as light modulation and highly nonlinear & bistable optical device
Nano-electromechanical switchable photonic metamaterials
We introduce mechanically reconfigurable electrostatically-driven photonic metamaterials (RPMs) as a generic platform for large-range tuning and switching of photonic metamaterial properties. Here we illustrate this concept with a high-contrast metamaterial electro-optic switch exhibiting relative reflection changes of up to 72% in the optical part of the spectrum
Coherent control of birefringence and optical activity
Control of polarization of light with light is demonstrated in thin slabs of linear material promising ultrafast all-optical data processing at arbitrarily low intensities. In proof-of-principle experiments we access any polarization azimuth and any ellipticity
Solid-immersion super-oscillatory lens for heat assisted magnetic recording technology and nanoscale imaging
We demonstrate a solid-immersion super-oscillatory planar lens for super-resolution applications with a 102 nm full-width at half maximum focal spot in a low-loss immersion medium
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