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We study transmission and reflection properties of a perfectly amplifying as well as absorbing medium analytically by using the tight binding equation. Different expressions for transmittance and reflectance are obtained for even and odd…

Condensed Matter · Physics 2009-10-31 P. K. Datta

Metallic rugate structures are theoretically investigated for achieving perfect absorption in the visible and near-infrared regions. Our model builds on nanoporous metal films whose porosity (volume fraction of voids) follows a sine-wave…

Optics · Physics 2012-05-29 Shiwei Shu , Yang Yang Li

Scanning transmission X-ray microscopy and ptychography have become mature tools for high-resolution, element-specific imaging of nanoscale structures. However, transmission geometries impose stringent constraints on sample thickness and…

A theory of light reflection and transmission by an optically thin nanocomposite slab which contains randomly distributed metal nanoparticles (NPs) is developed. The underlying model takes into account the reflection of light scattered by…

Optics · Physics 2021-04-13 V. G. Bordo

Problems with sign-changing coefficients occur, for instance, in the study of transmission problems with metamaterials. In this work, we present and analyze a generalized finite element method in the spirit of the Localized Orthogonal…

Numerical Analysis · Mathematics 2020-08-28 Théophile Chaumont-Frelet , Barbara Verfürth

We extend the first-principles analysis of attosecond transient absorption spectroscopy to two-dimensional materials. As an example of two-dimensional materials, we apply the analysis to monolayer hexagonal boron nitride (h-BN) and compute…

Materials Science · Physics 2019-07-19 Shunsuke A. Sato , Hannes Hübener , Umberto De Giovannini , Angel Rubio

A nonsingular analytical solution for the transfer equation in a pure absorber is obtained in central symmetry and in a monochromatic radiation field. The native regular singularity of the equation is removed by applying a linear…

Astrophysics · Physics 2007-05-23 C. H. Aboughantous

We investigate dynamic properties of inhomogeneous nano-materials, which appear in analytical descriptions typically as series of $\delta$-functions with corresponding Gibbs weights. We focus on observables relevant for transport theories…

Mesoscale and Nanoscale Physics · Physics 2013-01-14 N. M. Chtchelkatchev , A. Glatz

We report a new lensless microscopy configuration by integrating the concepts of transverse translational ptychography and defocus multi-height phase retrieval. In this approach, we place a tilted image sensor under the specimen for…

Image and Video Processing · Electrical Eng. & Systems 2021-11-03 Shaowei Jiang , Chengfei Guo , Patrick Hu , Derek Hu , Pengming Song , Tianbo Wang , Zichao Bian , Zibang Zhang , Guoan Zheng

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…

Optics · Physics 2016-08-25 Jacob Linder , Klaus Halterman

Plasmonic materials and metamaterials have been widely utilized to achieve spectral transmission, reflection and absorption filters based on localized or delocalized resonances arising from the interaction of photons with nanostructured…

Optics · Physics 2014-10-30 Zhongyang Li , Serkan Butun , Koray Aydin

We report a new strategy to remove the reflections resulted from the finite embedded transformation-optical design by proposing an impedance-tunable coordinate transformation, on which the functions of impedance coefficients can be derived…

Optics · Physics 2015-06-18 Jun Cao , Lifa Zhang , Senlin Yan , Xiaohan Sun

To overcome the resolution limit of conventional optics, near field imaging techniques using a negative index flat lens (NIFL) have been previously developed that amplify the evanescent components of the incident field. Here, a technique is…

Optics · Physics 2016-12-23 Wyatt Adams , Durdu Ö. Güney

The authors study theoretically reflection on the surface of a metamaterial with a hyperbolic dispersion. It is found that reflection is strongly dependent on how the surface is terminated with respect to the asymptote of the hyperbolic…

Optics · Physics 2008-11-10 Xin Li , Zixian Liang , Xiaohan Liu , Xunya Jiang , Jian Zi

We investigate the passivity constraints on the relations between transmission, reflection, and absorption eigenvalues in linear time-invariant systems. Using techniques from matrix analysis, we derive necessary and sufficient conditions…

Optics · Physics 2024-10-08 Cheng Guo , Shanhui Fan

Atomic-resolution imaging with scanning transmission electron microscopy is a powerful tool for characterizing the nanoscale structure of materials, in particular features such as defects, local strains, and symmetry-breaking distortions.…

Partial-transfer absorption imaging is a tool that enables optimal imaging of atomic clouds for a wide range of optical depths. In contrast to standard absorption imaging, the technique can be minimally-destructive and can be used to obtain…

Generalized-ensemble simulations enable the study of complex adsorption scenarios of a coarse-grained model polymer near an attractive nanostring, representing an ultrathin nanowire. We perform canonical and microcanonical statistical…

Soft Condensed Matter · Physics 2015-10-05 Thomas Vogel , Jonathan Gross , Michael Bachmann

We study a $d=2$ discrete solid--on--solid model of complete wetting of a rough substrate with random self--affine boundary, having roughness exponent $\zeta_s$. A suitable transfer matrix approach allows to discuss adsorption isotherms, as…

Condensed Matter · Physics 2009-10-22 G. Giugliarelli , A. L. Stella

Metagratings have been shown to form an agile and efficient platform for extreme wavefront manipulation, going beyond the limitations of gradient metasurfaces. Previous approaches for transmissive metagratings have resorted on compound…