English
Related papers

Related papers: Reflectivity spectra as absorption ones -- is it c…

200 papers

Relativistic reflection features in the X-ray spectra of accreting black holes are considered to be generated by the illumination of the accretion disk by the hot corona. In this work, we present a numerical method for the emission line…

High Energy Astrophysical Phenomena · Physics 2025-05-29 Yuan Feng , Ye-Fei Yuan , Shuang-Nan Zhang

We demonstrate that the metamaterial perfect absorber behaves as a meta-cavity bounded between a resonant metasurface and a metallic thin-film reflector. The perfect absorption is achieved by the Fabry-Perot cavity resonance via multiple…

Negative index of refraction has become an accepted part of transformation optics, which is encountered in transformations that change the orientation of the manifold. Based on this concept, various designs of perfect lenses have been…

Optics · Physics 2009-12-15 L. Bergamin

In this position paper, we consider the state of computer vision research with respect to invariance to the horizontal orientation of an image -- what we term reflection invariance. We describe why we consider reflection invariance to be an…

Computer Vision and Pattern Recognition · Computer Science 2015-06-09 Craig Henderson , Ebroul Izquierdo

The coherent reflectivity of a dense, relativistic, ultra-thin electron layer is derived analytically for an obliquely incident probe beam. Results are obtained by two-fold Lorentz transformation. For the analytical treatment, a plane…

Plasma Physics · Physics 2009-11-13 Hui-Chun Wu , Jürgen Meyer-ter-Vehn

We present results of an extensive suite of numerical simulations that probe square-tiled microwave absorber performance as a function of material properties, frequency, geometry, and unit cell size. The work, which probes both specular…

Instrumentation and Methods for Astrophysics · Physics 2025-11-10 Gaganpreet Singh , Rustam Balafendiev , Mahesh Singh Bist , Thomas J. L. J. Gascard , Gagandeep Kaur , Vid Primožič , Jon E. Gudmundsson

A vectorial analysis of magnetic resonance spectrometers, based on traveling wave resonators and including the reference arm and the automatic control of frequency, has been developed. The proposed model, valid also for stationary wave…

Instrumentation and Detectors · Physics 2015-06-26 G. Annino , M. Cassettari , M. Fittipaldi , M. Martinelli

While metasurfaces (MSs) are constructed from deeply-subwavelength unit cells, they are generally electrically large and full-wave simulations of the complete structure are computationally expensive. Thus, to reduce this high computational…

Applied Physics · Physics 2021-08-16 Ville Tiukuvaara , Tom. J. Smy , Karim Achouri , Shulabh Gupta

Optical spectroscopy techniques such as differential reflectance and transmittance have proven to be very powerful techniques to study 2D materials. However, a thorough description of the experimental setups needed to carry out these…

The capability of optical resonators to extend the effective radiation-matter interaction length originates from a multipass effect, hence is intrinsically limited by the resonator quality factor. Here, we show that this constraint can be…

Optics · Physics 2016-07-05 P. Malara , C. E. Campanella , A. Giorgini , S. Avino , P. De Natale , G. Gagliardi

Two methods of refractometry in reflected light from optical surface of samples are considered and studied experimentally. Methods are grounded on results of Fresnel theory of concerning light reflectivity at near normal incidence and…

Optics · Physics 2010-08-26 E. A. Tikhonov , V. A. Ivashkin

We present simple XSPEC models for fitting excess variance spectra of AGN. Using a simple Monte-Carlo approach, we simulate a range of spectra corresponding to physical parameters varying, then calculate the resulting variance spectra.…

High Energy Astrophysical Phenomena · Physics 2020-01-08 M. L. Parker , W. N. Alston , Z. Igo , A. C. Fabian

We consider the problem of imaging extended reflectors in terminating waveguides. We form the image by back-propagating the array response matrix projected on the waveguide's non-evanescent modes. The projection is adequately defined for…

Computational Physics · Physics 2017-11-30 Chrysoula Tsogka , Dimitrios A. Mitsoudis , Symeon Papadimitropoulos

We study the effect of spatial dispersion of crystal modes on optical properties such as the reflectivity $R$. As an example for isotropic media, we investigate the simplest model for phonons in ionic crystals and compare with previous…

Optics · Physics 2009-11-10 I. Kaelin , Ch. Helm , G. Blatter

Reflectionless potentials (RPs) represent a class of potentials that offer total transmission in the context of one dimensional scattering. Optical realization of RPs in stratified medium can exhibit broadband omnidirectional antireflection…

This paper describes how resonance spectra and mode profiles can be used to characterize and quantify the mode-shaping effects in open-access plano-concave optical microcavities. The presented semi-analytic theory is based on the…

By using the notion of wavelength- and angle-averaged reflectance, we assess in a systematic way the performance of finite omnidirectional reflectors. We put forward how this concept can be employed to optimize omnidirectional capabilities.…

Optics · Physics 2007-05-23 A. G. Barriuso , J. J. Monzon , L. L. Sanchez-Soto , A. Felipe

The diffraction spectrum of coherent waves scattered from fractal supports is calculated exactly. The fractals considered are of the class generated iteratively by successive dilations and translations, and include generalizations of the…

Condensed Matter · Physics 2009-10-28 Daniel A. Hamburger-Lidar

We tackle the problem of reflectance estimation from a set of multi-view images, assuming known geometry. The approach we put forward turns the input images into reflectance maps, through a robust variational method. The variational model…

Computer Vision and Pattern Recognition · Computer Science 2018-01-24 Jean Mélou , Yvain Quéau , Jean-Denis Durou , Fabien Castan , Daniel Cremers

We analyze the resonant variation of the optical reflection on an infiltrated artificial opal made of transparent nanospheres. The resonant infiltration is considered as a perturbation in the frame of a previously described one-dimensional…

Optics · Physics 2015-06-05 Isabelle Maurin , Daniel Bloch