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One-dimensional light harvesting structures with a realistic geometry nano-patterned on an opaque metallic film are optimized to render high transmission efficiencies at optical and infrared frequencies. Simple design rules are developed…

This paper describes a class of shape optimization problems for optical metamaterials comprised of periodic microscale inclusions composed of a dielectric, low-dimensional material suspended in a non-magnetic bulk dielectric. The shape…

Numerical Analysis · Mathematics 2024-01-08 Manaswinee Bezbaruah , Matthias Maier , Winnifried Wollner

Representing graphs as sets of node embeddings in certain curved Riemannian manifolds has recently gained momentum in machine learning due to their desirable geometric inductive biases, e.g., hierarchical structures benefit from hyperbolic…

Machine Learning · Computer Science 2020-06-09 Calin Cruceru , Gary Bécigneul , Octavian-Eugen Ganea

We describe a dispersive unit consisting of cascaded volume-phase holographic gratings for spectroscopic applications. Each of the gratings provides high diffractive efficiency in a relatively narrow wavelength range and transmits the rest…

Instrumentation and Methods for Astrophysics · Physics 2017-05-04 Eduard R. Muslimov , Gennady G. Valyavin , Sergei N. Fabrika , Nadezhda K. Pavlycheva

We extend the $t-z$ mapping formalism of time-dependent paraxial optics by identifying configurations displaying a synthetic magnetic vector potential, leading to a non-trivial band topology in propagating geometries. We consider an…

We demonstrate that metamaterial devices requiring anisotropic dielectric permittivity and magnetic permeability may be emulated by specially designed tapered waveguides. This approach leads to low-loss, broadband performance. Based on this…

High conversion efficiency between electrical and optical power is highly desirable both for high peak and high average power radiation sources. In this paper, we discuss a new mechanism based on stimulated superradiant emission in a…

Accelerator Physics · Physics 2014-10-30 Joseph Duris , Alex Murokh , Pietro Musumeci

Optical nanofibers provide a rich platform for exploring atomic and optical phenomena even when they support only a single spatial mode. Nanofibers supporting higher-order modes provide additional degrees of freedom to enable complex…

Quantum Physics · Physics 2015-09-15 Jonathan E. Hoffman , Fredrik K. Fatemi , Guy Beadie , Steven L. Rolston , Luis A. Orozco

Structural optimization is a popular method for designing objects such as bridge trusses, airplane wings, and optical devices. Unfortunately, the quality of solutions depends heavily on how the problem is parameterized. In this paper, we…

Machine Learning · Computer Science 2019-09-17 Stephan Hoyer , Jascha Sohl-Dickstein , Sam Greydanus

Finding the optimal embedding of networks into low-dimensional hyperbolic spaces is a challenge that received considerable interest in recent years, with several different approaches proposed in the literature. In general, these methods…

Physics and Society · Physics 2024-01-08 Bendegúz Sulyok , Gergely Palla

Waveguide design is crucial in developing efficient light delivery systems, requiring meticulous material selection, precise manufacturing, and rigorous performance optimization, including dispersion engineering. Here, we introduce…

Optics · Physics 2025-06-10 Yuntian Wang , Yuhang Li , Tianyi Gan , Kun Liao , Mona Jarrahi , Aydogan Ozcan

In this paper we present a mixed projection- and density-based topology optimization approach. The aim is to combine the benefits of both parametrizations: the explicit geometric representation provides specific controls on certain design…

Computational Engineering, Finance, and Science · Computer Science 2019-10-09 Nicolò Pollini , Oded Amir

We consider the time-harmonic scattering wave problem in a 2D waveguide at wavenumber $k$ such that one mode is propagating in the far field. In a first step, for a given $k$, playing with one scattering branch of finite length, we…

Analysis of PDEs · Mathematics 2019-05-22 Lucas Chesnel , Vincent Pagneux

We provide a computational method for quickly determining the correct distribution of optically active nanoparticles for a desired response. This is achieved by simulating the optical response of single nanoparticles and performing a…

Optics · Physics 2019-01-03 Phillip Manley , Min Song , Sven Burger , Martina Schmid

With the emergence of new photonic and plasmonic materials with optimized properties as well as advanced nanofabrication techniques, nanophotonic devices are now capable of providing solutions to global challenges in energy conversion,…

On the base of modified mode matching method we obtain some results that can be useful in the process of tuning of nonunifrom disk-loaded structures. Our consideration has shown that there are some parameters that depend only on the…

Accelerator Physics · Physics 2016-04-20 M. I. Ayzatsky , V. V. Mytrochenko

We investigate the propagation of transverse elastic waves in crumpled media. We set up the wave equation for transverse waves on a generic curved, strained surface via a Langrangian formalism and use this to study the scaling behaviour of…

Materials Science · Physics 2009-11-07 Ajay Gopinathan , T. A. Witten , S. C. Venkataramani

A class of algorithms for the solution of discrete material optimization problems in electromagnetic applications is discussed. The idea behind the algorithm is similar to that of the sequential programming. However, in each major iteration…

Optimization and Control · Mathematics 2017-07-14 Johannes Semmler , Lukas Pflug , Michael Stingl

In a free-electron laser equipped with variable-gap undulator modules, the technique of undulator tapering opens up the possibility to increase the radiation power beyond the initial saturation point, thus enhancing the efficiency of the…

Accelerator Physics · Physics 2016-08-31 Alan Mak , Francesca Curbis , Bart Faatz , Sverker Werin

We investigate a short (~1.5{\mu}m) partially-corrugated tapered waveguide structure for mode coupling from a silicon micro-slab to a plasmonic nano-gap waveguide at the optical communication frequency. More than 80% transmission efficiency…

Optics · Physics 2013-04-03 Y. Liu , Y. Lai