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This study formulates a volumetric inverse-design methodology to generate a pair of complementary focusing metalenses for terahertz imaging: the two lenses exhibit equal and opposite shifts in focal length with frequency. An asymmetry…

Optics · Physics 2025-02-18 Mo Chen , Ka Fai Chan , Alec M. Hammond , Chi Hou Chan , Steven G. Johnson

The alignment tolerance of multipoles on a girder is better than 30um in the storage ring of High Energy Photon Source HEPS which will be the next project at IHEP Institute of High Energy Physics. This is difficult to meet the precision…

Accelerator Physics · Physics 2015-09-02 Lei Wu , Xiaolong Wang , Chunhua Li , Huamin Qu

Highly accurate 3D volumetric reconstruction is still an open research topic where the main difficulty is usually related to merging some rough estimations with high frequency details. One of the most promising methods is the fusion between…

Computer Vision and Pattern Recognition · Computer Science 2019-08-05 Fotios Logothetis , Roberto Mecca , Roberto Cipolla

The method of the optical approximation is used to estimate the high frequency impedances of different vacuum chamber transitions of the European XFEL beam line. The approximations of the longitudinal impedances are obtained in terms of…

Accelerator Physics · Physics 2010-06-07 Martin Dohlus , Igor Zagorodnov , Olga Zagorodnova

This work is concerned with the inverse source problem of locating multiple multipolar sources from boundary measurements for the Helmholtz equation. We develop simple and effective sampling schemes for location acquisition of the sources…

Analysis of PDEs · Mathematics 2018-01-18 Deyue Zhang , Yukun Guo , Jingzhi Li , Hongyu Liu

We propose a new approach, multi-view Laplacian support vector machines (SVMs), for semi-supervised learning under the multi-view scenario. It integrates manifold regularization and multi-view regularization into the usual formulation of…

Machine Learning · Computer Science 2013-07-29 Shiliang Sun

A new sampling method for inverse scattering problems is proposed to process far field data of one incident wave. As the linear sampling method, the method sets up ill-posed integral equations and uses the (approximate) solutions to…

Analysis of PDEs · Mathematics 2018-08-01 Juan Liu , Jiguang Sun

An important problem that arises in many engineering applications is the boundary value problem for ordinary differential equations. There have been many computational methods proposed for dealing with this problem. The convergence of the…

Numerical Analysis · Mathematics 2019-07-17 Duggirala Meher Krishna , Duggirala Ravi

We introduce a novel framework for solving inverse problems using NeRF-style generative models. We are interested in the problem of 3-D scene reconstruction given a single 2-D image and known camera parameters. We show that naively…

Computer Vision and Pattern Recognition · Computer Science 2021-12-17 Giannis Daras , Wen-Sheng Chu , Abhishek Kumar , Dmitry Lagun , Alexandros G. Dimakis

Tightly focused optical fields are essential in nano-optics, but their applications have been limited by the challenges of accurate yet efficient characterization. In this article, we develop an in situ method for reconstructing the fully…

Optics · Physics 2024-08-28 Xin Liu , Shijie Tu , Yiwen Hu , Yifan Peng , Yubing Han , Cuifang Kuang , Xu Liu , Xiang Hao

It is challenging to align multi-exposed images due to large illumination variations, especially in presence of saturated regions. In this paper, a novel image alignment algorithm is proposed to cope with the multi-exposed images with…

Image and Video Processing · Electrical Eng. & Systems 2020-12-22 Jun Jiang , Zhengguo Li , Shoulie Xie , Shiqian Wu , Liangcai Zeng

``Vectorial'' numerical algorithms are proposed for solving the inverse and direct spectral scattering problems for the nonlinear vector Schroedinger equation, taking into account wave polarization, known as the Manakov system. It is shown…

Exactly Solvable and Integrable Systems · Physics 2020-06-09 Leonid L. Frumin

In this paper we present a hybrid approach to numerically solve two-dimensional electromagnetic inverse scattering problems, whereby the unknown scatterer is hosted by a possibly inhomogeneous background. The approach is `hybrid' in that it…

Analysis of PDEs · Mathematics 2012-10-22 G. Giorgi , M. Brignone , R. Aramini , M. Piana

We have taken advantage of the implementation of an adaptive optics system on the Themis solar telescope to implement innovative strategies based on an inverse problem formulation for the control loop. Such an approach encompassing the…

Instrumentation and Methods for Astrophysics · Physics 2023-11-30 Éric Thiébaut , Michel Tallon , Isabelle Tallon-Bosc , Bernard Gelly , Richard Douet , Maud Langlois , Gil Moretto

Several applications require spatial distributions of the incident electric field that maximize the electric field at a focal point for a given input power. The field distributions are derived for various optical systems in a direct way…

Optics · Physics 2011-10-18 Markus Sondermann , Norbert Lindlein , Gerd Leuchs

In this work, we address the problem of jointly estimating albedo, normals, depth and 3D spatially-varying lighting from a single image. Most existing methods formulate the task as image-to-image translation, ignoring the 3D properties of…

Computer Vision and Pattern Recognition · Computer Science 2021-10-22 Zian Wang , Jonah Philion , Sanja Fidler , Jan Kautz

Simple semitoric systems were classified about ten years ago in terms of a collection of invariants, essentially given by a convex polygon with some marked points corresponding to focus-focus singularities. Each marked point is endowed with…

Symplectic Geometry · Mathematics 2020-02-14 Álvaro Pelayo

Camera arrays provide spatial and angular information within a single snapshot. With refocusing methods, focal planes can be altered after exposure. In this letter, we propose a light field refocusing method to improve the imaging quality…

Image and Video Processing · Electrical Eng. & Systems 2021-08-29 Yingqian Wang , Jungang Yang , Yulan Guo , Chao Xiao , Wei An

Achieving quantum-limited motional control of optically trapped particles beyond the sub-micrometer scale is an outstanding problem in levitated optomechanics. A key obstacle is solving the light scattering problem and identifying particle…

Optics · Physics 2025-07-15 Moosung Lee , Benjamin A. Stickler , Thomas Pertsch , Sungkun Hong

A slab of negatively refracting material, thickness d, can focus an image at a distance 2d from the object. The negative slab cancels an equal thickness of positive space. This result is a special case of a much wider class of focussing:…

Condensed Matter · Physics 2009-11-10 J. B. Pendry , S. Anantha Ramakrishna
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