相关论文: Reconfigurable photoinduced metamaterials in the m…

We theoretically investigate the terahertz dielectric response of a semiconductor slab hosting an infrared photoinduced grating. The periodic structure is due to the charge carries photo-excited by the interference of two tilted infrared…

A metamaterial structure consisting of a one-dimensional metal/air-gap subwavelength grating is investigated for optical antireflection coating on germanium substrate in the infrared regime. For incident light polarized perpendicularly to…

We examine some of the optical properties of a metamaterial consisting of thin layers of alternating metal and dielectric. We can model this material as a homogeneous effective medium with anisotropic dielectric permittivity. When the…

We propose and demonstrate subwavelength grating (SWG) metamaterial waveguides and ring resonators on a silicon nitride platform for the first time. The SWG waveguide is engineered such that a large overlap of 53% of the Bloch mode with the…

This work focuses on optical multiplexers for mid-IR broadband source in gas sensing application. The design of multiplexer configurations based on two types of diffraction gratings is discussed. Owing to utility of Gaussian approximation…

As the variation of temperature alters the intrinsic carrier density in a semiconductor, numerical simulations indicate that the consequent variation of the relative permittivity in the terahertz regime provides a way to realize thermally…

We theoretically consider infrared-driven hyperbolic metamaterials able to spatially filtering terahertz radiation. The metamaterial is a slab made of alternating semiconductor and dielectric layers whose homogenized uniaxial response, at…

Fully reconfigurable metasurfaces would enable new classes of optical devices that provide unprecedented control of electromagnetic beamforms. The principal challenge for achieving reconfigurability is the need to generate large tunability…

The interplay between electronic properties and optical response enables the realization of novel types of materials with tunable responses. Superconductors are well known to exhibit profound changes in the electronic structure related to…

Subwavelength gratings play a fundamental and pivotal role in numerous science and applications for wave manipulation, exhibiting distinctive features such as filtering, phase manipulation, and anti-reflection. However, conventional…

We present a technique capable of producing subwavelength focal spots in the far-field of the source in planar non-resonant structures. The approach combines the diffraction gratings that generate the high-wavevector-number modes and planar…

We investigate the absorption properties of graphene-based anisotropic metamaterial structures where the metamaterial layer possesses an electromagnetic response corresponding to a near-zero permittivity. We find that through analytical and…

Emerging technology based on artificial materials containing metallic structures has raised the prospect for unprecedented control of terahertz waves through components like filters, absorbers and polarizers. The functionality of these…

Plasmonic gratings constitute a paradigmatic instance of the wide range of applications enabled by plasmonics. While subwavelength metal gratings find applications in optical biosensing and photovoltaics, atomically thin gratings achieved…

Reconfigurable metamaterial-based apertures can play a unique role in both imaging and in beam-forming applications, where current technology relies mostly on the fabrication and integration of large detector or antenna arrays. Here, we…

Metamaterials are artificially created media, which allow introducing additional degrees of freedom into electromagnetic design by controlling constitutive material parameters. Reconfigurable time-dependent metamaterials can further enlarge…

This work numerically investigates the radiative properties of film-coupled metamaterials made of a two-dimensional metallic concave grating on a continuous metal film separated by an ultrathin dielectric spacer. Spectrally-selective…

Angle-selective optical devices are of importance to several applications such as photovoltaics, high-sensitivity photodetectors and displays. There are several approaches to realizing angular selectivity, but it remains challenging to…

We studied a metasurface constituted as a periodic array of semiconductor split-ring resonators. The resonance frequencies of the metasurface excited by normally incident light were found to be continuously tunable in the terahertz regime…

Metamaterials--artificially structured materials with tailored electromagnetic response--can be designed to have properties difficult to achieve with existing materials. Here we present a structured metamaterial, based on conducting split…