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Related papers: X-Ray Propagation in Tapered Waveguides: Simulatio…

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The question on X-ray extreme focusing (smallest reachable spot size) brings us to the idea for using the wave features of X-ray propagation in media. As known, wave features are revealed at propagation in ultra-narrow collimators as well…

Optics · Physics 2009-11-13 S. B. Dabagov

The problem of optimization of propagation-based phase-contrast imaging setups is considered in the case of projection X-ray imaging and three-dimensional tomography with phase retrieval. For two-dimensional imaging, a simple model for a…

Medical Physics · Physics 2026-03-03 T. E. Gureyev , D. M. Paganin , H. M. Quiney

A new method for investigation of x-ray propagation in a rough narrow dielectric waveguide is proposed on the basis of the numerical integration of the quazioptical equation. In calculations a model rough surface was used with the given…

Optics · Physics 2007-05-23 T. A. Bobrova , L. I. Ognev

Waveguide Meshes are efficient and versatile models of wave propagation along a multidimensional ideal medium. The choice of the mesh geometry affects both the computational cost and the accuracy of simulations. In this paper, we focus on…

Numerical Analysis · Mathematics 2024-09-21 Federico Fontana , Davide Rocchesso

We propose the combination of forward shape derivatives and the use of an iterative inversion scheme for Bayesian optimization to find optimal designs of nanophotonic devices. This approach widens the range of applicability of Bayesian…

Computational Physics · Physics 2021-01-12 Xavier Garcia-Santiago , Sven Burger , Carsten Rockstuhl , Philipp-Immanuel Schneider

We present a new approach for simulating x-ray nanobeam Bragg coherent diffraction patterns based on the Takagi-Taupin equations. Compared to conventional methods, the current approach can be universally applied to any weakly strained…

Mesoscale and Nanoscale Physics · Physics 2024-07-12 T. Zhou , M. J. Cherukara , S. Kandel , M. Allain , N. Hua , O. Shpyrko , Y. Takamura , Z. Cai , S. O. Hruszkewycz , M. V. Holt

In this paper we suggest and theoretically study a tapered plasmonic nanostructure which connects the incident wave beam with a subwavelength spatial region where the field is locally enhanced in a broad frequency range or for different…

Optics · Physics 2011-04-05 O. Luukkonen , J. Pniewski , C. Simovski

Paganin's method for image reconstruction in propagation-based phase-contrast X-ray imaging and tomography has enjoyed broad acceptance in recent years, with over one thousand publications citing its use. The present paper discusses…

Medical Physics · Physics 2026-01-13 Timur E. Gureyev , David M. Paganin , Ashkan Pakzad , Harry M. Quiney

Beam propagation beyond the paraxial approximation is studied in an optically written waveguide structure. The waveguide structure that leads to diffractionless light propagation, is imprinted on a medium consisting of a five-level atomic…

Optics · Physics 2013-05-08 L. Zhang , T. N. Dey , J. Evers

The finite-difference time-domain method was employed to simulate light propagation in tapered near-field fiber probes with small metal aperture. By conducting large-volume simulations, including tapered metal-cladding waveguide and…

Waveguides offer a means to controllably couple atomic ensembles to the electromagnetic field therein. Here, we demonstrate x-ray propagation in planar thin-film waveguides coupled to M\"ossbauer nuclei under collective resonant excitation…

Conventional X-ray methods use incoming plane waves and result in discrete diffraction patterns when scattered at crystals. Here we find, by a systematic method, incoming waveforms which exhibit discrete diffraction patterns when scattered…

Optics · Physics 2015-06-16 Gero Friesecke , Richard D. James , Dominik Jüstel

The evolution from 3rd to 4th generation synchrotron radiation (SR) sources provide promising potential improvements in X-ray techniques, particularly in spatial resolution for imaging, temporal resolution for dynamic studies, and beam size…

Optics · Physics 2025-03-19 Han Xu , Xiao Li , Ming Li , Zhe Ren , Yi Zhang , Peng Liu , Yuhui Dong , Liang Zhou

The interaction of electromagnetic waves with pairs of nanotubes having arbitrary-shaped cross sections is investigated. The study starts by thoroughly examining nanotube couples with circular boundaries to identify the structural, textural…

We analyze long range wave propagation in three-dimensional random waveguides. The waves are trapped by top and bottom boundaries, but the medium is unbounded in the two remaining directions. We consider scalar waves, and motivated by…

Analysis of PDEs · Mathematics 2012-11-05 Liliana Borcea , Josselin Garnier

In a previous paper, we reviewed theoretically some of the available processing schemes for X-ray wavefront sensing based on random modulation. We here show experimental applications of the technique for characterising both refractive and…

Instrumentation and Detectors · Physics 2020-02-24 Sebastien Berujon , Ruxandra Cojocaru , Pierre Piault , Rafael Celestre , Thomas Roth , Raymond Barrett , Eric Ziegler

I derive directional wave equations useful for pulses propagating in beam, rod, pipe, and disk geometries by using a cylindrical coordinate system; the scheme works equally well for either long multi-cycle or single-cycle ultrashort pulses.…

Optics · Physics 2012-10-26 Paul Kinsler

We present exact bright, dark and rogue soliton solutions of generalized higherorder nonlinear Schrodinger equation, describing the ultrashort beam propagation in tapered waveguide amplifier, via a similarity transformation connected with…

Pattern Formation and Solitons · Physics 2020-10-30 Harneet Kaur , Nisha , Amit Goyal , Thokala Soloman Raju , C. N. Kumar

In 3D single particle imaging with X-ray free-electron lasers, particle orientation is not recorded during measurement but is instead recovered as a necessary step in the reconstruction of a 3D image from the diffraction data. Here we use…

Data Analysis, Statistics and Probability · Physics 2016-05-25 Julien Flamant , Nicolas Le Bihan , Andrew V. Martin , Jonathan H. Manton

For the reliable fabrication of the current and next generation of nanostructures it is essential to be able to determine their material composition and dimensional parameters. Using the grazing incidence X-ray fluoresence technique, which…

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