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Absorption is a crucial parameter in shaping wave propagation dynamics, yet achieving ultra-broadband absorption remains highly challenging, particularly in balancing low-frequency and broad bandwidth. Here, we present a metamaterial…

Applied Physics · Physics 2024-11-04 Nengyin Wang , Sibo Huang , Zhiling Zhou , Din Ping Tsai , Jie Zhu , Yong Li

Resonances, also known as quasinormal modes (QNM) in the non-Hermitian case, play a ubiquitous role in all domains of physics ruled by wave phenomena, notably in continuum mechanics, acoustics, electrodynamics, and quantum theory. The…

In order to improve low-frequency characteristics of micro-perforated panel absorbers, sound absorption structures composed of micro-perforated panels and expansion chambers are design, and an optimization design method is constructed based…

Audio and Speech Processing · Electrical Eng. & Systems 2023-05-31 Xiaoming Wang , Chen Liang , Yulin Mei

The equations of motion in a macroscopically inhomogeneous porous medium saturated by a fluid are derived. As a first verification of the validity of these equations, a two-layer rigid frame porous system considered as one single porous…

We describe a method for calculating the probability with which the wall of a plasma absorbs an electron at low energy. The method, based on an invariant embedding principle, expresses the electron absorption probability as the probability…

Plasma Physics · Physics 2017-01-10 Franz X. Bronold , Holger Fehske

We explore the scattering of waves in designed asymmetric one-dimensional waveguide networks. We show that the reflection between two ports of an asymmetric network can be identical over a broad frequency range, as if the network was…

Past work has considered the analytic properties of the reflection coefficient for a metal-backed slab. The primary result established a fundamental relationship for the minimal layer thickness to bandwidth ratio achievable for an absorber.…

Optics · Physics 2023-12-18 Willie J. Padilla , Yang Deng , Omar Khatib , Vahid Tarokh

We experimentally demonstrate increased transmission of light through strongly scattering materials. Wavefront shaping is used to selectively couple light to the open transport channels in the material, resulting in an increase of up to 44%…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 I. M. Vellekoop , A. P. Mosk

In this paper we present an approach for the generalization of adsorption of light gases in porous materials. This new theory goes beyond the Langmuir and BET theories, which are the standard approaches that have limited application to…

Materials Science · Physics 2018-03-28 Alexander A. Aduenko , Andy Murray , Jose L. Mendoza-Cortes

In this paper, a plasmonic absorber consisting of a metal-dielectric-metal stack with a top layer of Sierpinski nanocarpet is theoretically investigated. Such compact absorber depicts broadband angle-independent behavior over a wide optical…

Optics · Physics 2016-06-01 Ali Eshaghian , Sajjad AbdollahRamezani , Ata Chizari , Amin Khavasi

The concept of the broadband epsilon-near-zero meta-atom consisting of layered stacks with specified metallic filling ratio and thickness is proposed based on the Bergman spectral representation of the effective permittivity. The step-like…

Optics · Physics 2015-06-15 Lei Sun , Jie Gao , Xiaodong Yang

We report the experimental design of a 1D stealth acoustic material, namely a material that suppresses the acoustic scattering for a given set of incident wave vectors. The material consists of multiple scatterers, rigid diaphragms, located…

Applied Physics · Physics 2019-06-05 V. Romero-García , N. Lamothe , G. Theocharis , O. Richoux , L. M. García-Raffi

A theory of light reflection and transmission by an optically thin nanocomposite slab which contains randomly distributed metal nanoparticles (NPs) is developed. The underlying model takes into account the reflection of light scattered by…

Optics · Physics 2021-04-13 V. G. Bordo

Spatially exponential distributions of material properties are ubiquitous in many natural and engineered systems, from the vertical distribution of the atmosphere to acoustic horns and anti-reflective coatings. These media seamlessly…

Applied Physics · Physics 2024-04-09 Sichao Qu , Min Yang , Tenglong Wu , Yunfei Xu , Nicholas Fang , Shuyu Chen

In this paper, we introduce a novel, adapted approach for computing gas adsorption properties in porous materials. We analyze the Dubinin-Polanyi's adsorption model and investigate various frameworks to estimate its required essential…

Materials Science · Physics 2023-10-25 F. Stavarache , A. Luna-Triguero , S. Calero , J. M. Vicent-Luna

We study the electromagnetic scattering by multilayered biperiodic aggregates of dielectric layers and gratings of conducting plates. We show that the characteristic lengths of such structures provide a good control of absorption bands. The…

Optics · Physics 2008-02-03 G. Berginc , C. Bourrely , C. Ordenovic , B. Torresani

Complete absorption of electromagnetic waves is paramount in today's applications, ranging from photovoltaics to cross-talk prevention into sensitive devices. In this context, we use a genetic algorithm (GA) strategy to optimize absorption…

The calculation of the transfer matrix for a large non-periodic multilayered system may become unstable in the presence of absorption. We discuss the origin of this instability and we explore two methods to overcome it: the use of a total…

Many applications seek to measure a sample's absorption coefficient spectrum to retrieve the chemical makeup. Many real world samples are optically turbid, causing scattering confounds which many commercial spectrometers cannot address.…

Optics · Physics 2023-01-05 Giles Blaney , Angelo Sassaroli , Sergio Fantini

Impedance mismatch between free space and absorptive materials is a fundamental issue plaguing the pursue of high-efficiency light absorption. In this work, we design and numerically demonstrate a type of non-resonant impedance-matched…

Optics · Physics 2021-08-09 Huiying Fan , Jensen Li , Yun Lai , Jie Luo