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Related papers: Optical cages made of graphitic frameworks

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We examine array of metal-mesh frameworks for their wide-band absorption. These take the form of quasi-crystal optical cages. An array of cages tends to focus the incoming radiation within each framework. An array of cage-within-cage…

Optics · Physics 2019-07-09 V. Kumar , J. P. Walker , H. Grebel

Far infrared(FIR) data on the optical properties of graphite are presently lacking. An important step towards filling this gap was taken by Kuzmenko et al. (2008) who measured, on HOPG (Highly Oriented Pyrolitic Graphite) at normal…

Astrophysics of Galaxies · Physics 2015-06-22 Robert J. Papoular , Renaud Papoular

The optical absorptions of different Au32 isomers in the whole frequency range from the far-infrared (FIR) to near-ultraviolet (UV) have been calculated using the relativistic density-functional method in order to identify their geometrical…

Materials Science · Physics 2007-05-23 Wei Fa , Jian Zhou , Chuanfu Luo , Jinming Dong

The electronic structure and optical response of electrically gated bilayer graphene are studied by first-principles approaches. We have obtained the induced band gap that is in good agreement with experiment when the applied electric field…

Mesoscale and Nanoscale Physics · Physics 2015-03-13 Li Yang

Diamond 1 - 10 micrometers thick membranes are platform for photonic, quantum and opto-mechanic devices with applications across UV-IR spectral ranges. IR characterization of diamond gratings in reflection and transmission showed a change…

A simple analysis is performed for the absorption properties of graphene; sandwiched between two media. For a proper choice of media and graphene doping/gating one can approach 50-100% absorption in the GHz-THz range for the one atom thick…

Optics · Physics 2012-01-17 S. P. Apell , G. W. Hanson , C. Hägglund

We report on spectroscopy results from the mid- to far-infrared on wafer-scale graphene, grown either epitaxially on silicon carbide, or by chemical vapor deposition. The free carrier absorption (Drude peak) is simultaneously obtained with…

Mesoscale and Nanoscale Physics · Physics 2011-11-17 Hugen Yan , Fengnian Xia , Wenjuan Zhu , Marcus Freitag , Christos Dimitrakopoulos , Ageeth A. Bol , George Tulevski , Phaedon Avouris

The versatile control of graphene's plasmonic modes via an external gate-voltage inspires us to design efficient electro-optical graphene plasmonic logic gates at the midinfrared wavelengths. We show that these devices are superior to the…

Mesoscale and Nanoscale Physics · Physics 2014-05-08 Kelvin J. A. Ooi , Hong Son Chu , Ping Bai , Lay Kee Ang

The transient response of an intrinsic graphene, which is caused by the ultrafast interband transitions, is studied theoretically for the range of pumping correspondent to the saturated absorption regime. Spectral and temporal dependencies…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 F. T. Vasko

Spectral imagers, the classic example being the color camera, are ubiquitous in everyday life. However, most such imagers rely on filter arrays that absorb light outside each spectral channel, yielding ~1/N efficiency for an N-channel…

Optics · Physics 2021-02-03 Jordan A. Goldstein , Dirk R. Englund

High-reflectance in many state-of-the-art optical devices is achieved with noble metals. However, metals are limited by losses, and for certain applications, by their high mass density. Using a combination of ab initio and optical transfer…

Thermal infrared (IR) radiation has attracted considerable attention due to its applications ranging from radiative cooling to thermal management. In this paper, we design a multi-band graphene-based metamaterial absorber compatible with…

One-dimensional light harvesting structures with a realistic geometry nano-patterned on an opaque metallic film are optimized to render high transmission efficiencies at optical and infrared frequencies. Simple design rules are developed…

Since graphene was synthesized the interest for building new 2D and 3D structures based on the carbon allotropes has been growing every day. One of these 3D structures is know as carbon schwarzites. Schwarzites consist of carbon…

Materials Science · Physics 2020-08-26 Raphael M. Tromer , Levi C. Felix , Cristiano F. Woellner , Douglas S. Galvao

The electronic properties of graphene are unique and are attracting increased attention to this novel 2-dimensional system. Its photonic properties are not less impressive. For example, this single atomic layer absorbs through direct…

Materials Science · Physics 2009-12-25 Fengnian Xia , Thomas Mueller , Yu-ming Lin , Alberto Valdes-Garcia , Phaedon Avouris

We theoretically investigate ultrafast and nonlinear optical properties of graphite thin films based on first-principles time-dependent density functional theory. We first calculate electron dynamics in a unit cell of graphite under a…

Laboratory measurements are used to constrain the dielectric tensor for graphite, from microwave to X-ray frequencies. The dielectric tensor is strongly anisotropic even at X-ray energies. The discrete dipole approximation is employed for…

Astrophysics of Galaxies · Physics 2016-11-09 B. T. Draine

We present 6-GHz Very Large Array radio images of 70 gravitational lens systems at 300-mas resolution, in which the source is an optically-selected quasar, and nearly all of which have two lensed images. We find that about in half of the…

Astrophysics of Galaxies · Physics 2024-04-05 Neal Jackson , Shruti Badole , Thomas Dugdale , Hannah R. Stacey , Philippa Hartley , J. P. McKean , .

We experimentally realized an optical nanofiber-based cavity by combining a 1-D photonic crystal and Bragg grating structures. The cavity morphology comprises a periodic, triplex air-cube introduced at the waist of the nanofiber. The cavity…

Optics · Physics 2017-08-02 Wenfang Li , Jinjin Du , Viet Giang Truong , Sile Nic Chormaic

We experimentally demonstrate a wide band near perfect light absorber in the mid-wave infrared region using multiplexed plasmonic metal structures. The wide band near perfect light absorber is made of two different size gold metal squares…

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