English
Related papers

Related papers: General method for focusing of waves using phase a…

200 papers

A perfectly collimated beam can be spread out by multiple scattering, creating a speckle pattern and increasing the etendue of the system. Standard optical systems conserve etendue, and thus are unable to reverse the process by transforming…

Optics · Physics 2021-07-23 Alba M. Paniagua-Diaz , William L. Barnes , Jacopo Bertolotti

We give an infinite class of exact analytical solutions for monochromatic light beams with strong focusing. As the solutions do not contain integrals, they are easy to explore compared with diffraction-theory results for strongly focused…

Optics · Physics 2018-09-26 T. G. Philbin

This paper introduces a new algorithm to improve the accuracy of numerical phase-averaging in oscillatory, multiscale, differential equations. Phase-averaging is a timestepping method which averages a mapped variable to remove highly…

Numerical Analysis · Mathematics 2024-11-07 Timothy C. Andrews , Beth A. Wingate

A new version of the invariant imbedding theory for the propagation of coupled waves in inhomogeneous media is applied to the mode conversion of high frequency electromagnetic waves into electrostatic modes in cold, magnetized and…

Plasma Physics · Physics 2009-11-11 Kihong Kim , Dong-Hun Lee

This report presents the results of a multi-scale wavelet based scheme for single image de-hazing and underwater image enhancement. The scheme is fast and highly localized in addition to global enhancement of hazy images. A PDE-based…

Computer Vision and Pattern Recognition · Computer Science 2021-12-01 Uche A. Nnolim

Divergent wave imaging with coherent compounding allows obtaining broad field of view and higher frame rate with respect to line by line insonification. However, the spatial and contrast resolution crucially depends on the weights applied…

Medical Physics · Physics 2025-10-21 Zahraa Alzein , Marco Crocco , Daniele D. Caviglia

Recently, we have discovered a new concept of permanent wave resonance with potential spatial oscillations. This means the constant wave swinging frequency on the whole energy intervals of spectral forbidden zones destroying physical…

Quantum Physics · Physics 2008-03-13 B. N. Zakhariev , V. M. Chabanov

This paper investigates quantum diffusion of matter waves in two-dimensional random potentials, focussing on expanding Bose-Einstein condensates in spatially correlated optical speckle potentials. Special care is taken to describe the…

Disordered Systems and Neural Networks · Physics 2009-11-13 C. Miniatura , R. C. Kuhn , D. Delande , C. A. Mueller

Planar travelling waves on $\mathbb R^d,$ with $ d\geq 2,$ are shown to persist in systems of reaction-diffusion equations with multiplicative noise on significantly long timescales with high probability, provided that the wave is orbitally…

Analysis of PDEs · Mathematics 2025-04-15 Mark van den Bosch , Hermen Jan Hupkes

This paper aims at developing new shape functions adapted to smooth vanishing coefficients for scalar wave equation. It proposes the numerical analysis of their interpolation properties. The interpolation is local but high order convergence…

Numerical Analysis · Mathematics 2019-08-16 Lise-Marie Imbert-Gerard

The applied method of the amplitude envelopes give us the possibility to describe a new class of amplitude equations governing the propagation of optical pulses in media with dispersion, dispersionless media and vacuum. We normalized these…

Pattern Formation and Solitons · Physics 2007-05-23 Lubomir M. Kovachev

The standing surface waves in a rectangular vertically oscillating vessel filled with water (Faraday waves) in the presence of a floating elastic sheet are studied experimentally and theoretically. The threshold amplitude of the instability…

Fluid Dynamics · Physics 2023-07-11 Vahideh Sardari , Leila Bahmani , Maniya Maleki

We pursue a low-wavenumber, second-order homogenized solution of the time-harmonic wave equation at both low and high frequency in periodic media with a source term whose frequency resides inside a band gap. Considering the wave motion in…

Analysis of PDEs · Mathematics 2021-02-23 Shixu Meng , Othman Oudghiri-Idrissi , Bojan B. Guzina

Frequency upconversion of an electromagnetic wave can occur in ionized plasma with decreasing electric permittivity and in split-ring resonator-structure metamaterials with decreasing magnetic permeability. We develop a general theory to…

Plasma Physics · Physics 2018-08-14 Kenan Qu , Qing Jia , Matthew R. Edwards , Nathaniel J. Fisch

We propose and demonstrate theoretically a method to achieve and design optical nonlinear responses through a light-mediated spatial hybridization of different standard nonlinearities. The mechanism is based on the fact that optical…

Optics · Physics 2008-04-24 Alessandro Ciattoni , Eugenio Del Re , Carlo Rizza , Andrea Marini

Modal phase matching (MPM) is a widely used phase matching technique in Al$_x$Ga$_{1-x}$As and other $\chi^{(2)}$ nonlinear waveguides for efficient wavelength conversions. The use of a non-fundamental spatial mode compensates the material…

Optics · Physics 2021-12-30 Dongpeng Kang , Weiqi Zhang , Amr S. Helmy , Siyuan Yu , Liying Tan , Jing Ma

In this work we present the results of calculation of the electric field distribution in the inhomogeneous media based on the generalized WKB method. In this approach the field is represented as the sum of two components, one of which is…

Optics · Physics 2024-12-05 M. I. Ayzatsky

We present a collection of well-conditioned integral equation methods for the solution of electrostatic, acoustic or electromagnetic scattering problems involving anisotropic, inhomogeneous media. In the electromagnetic case, our approach…

Numerical Analysis · Mathematics 2018-05-15 Lise-Marie Imbert-Gerard , Felipe Vico , Leslie Greengard , Miguel Ferrando

Generally, wave field reconstructions obtained by phase-retrieval algorithms are noisy, blurred and corrupted by various artifacts such as irregular waves, spots, etc. These disturbances, arising due to many factors such as non-idealities…

Optics · Physics 2012-07-24 Artem Migukin , Mostafa Agour , Vladimir Katkovnik

Phase modulation has come to be recognized as a fundamental paradigm for optical device design in applications involving the spatiotemporal control of optical wavefronts. Here, asymmetric resonant multilayer cavities based on the inclusion…

Optics · Physics 2023-07-26 Giuseppina Simone
‹ Prev 1 8 9 10 Next ›