Boundary-layer effects on electromagnetic and acoustic extraordinary transmission through narrow slits
File(s)
Accepted version
Author(s)
Brandão, Rodolfo
Holley, Jacob
Schnitzer, Ory
Type
Journal Article
Abstract
We study the problem of resonant extraordinary transmission of electromagnetic and acoustic waves through subwavelength slits in an infinite plate, whose thickness is close to a half-multiple of the wavelength. We build on the matched-asymptotics analysis of Holley & Schnitzer (2019 Wave Motion91, 102381 (doi:10.1016/j.wavemoti.2019.102381)), who considered a single-slit system assuming an idealized formulation where dissipation is neglected and the electromagnetic and acoustic problems are analogous. We here extend that theory to include thin dissipative boundary layers associated with finite conductivity of the plate in the electromagnetic problem and viscous and thermal effects in the acoustic problem, considering both single-slit and slit-array configurations. By considering a distinguished boundary-layer scaling where dissipative and diffractive effects are comparable, we develop accurate analytical approximations that are generally valid near resonance; the electromagnetic–acoustic analogy is preserved up to a single parameter that is provided explicitly for both scenarios. The theory is shown to be in excellent agreement with GHz-microwave and kHz-acoustic experiments in the literature.
Date Issued
2020-10-28
Date Acceptance
2020-09-25
Citation
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2020, 476 (2242)
ISSN
1364-5021
Publisher
The Royal Society
Journal / Book Title
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
Volume
476
Issue
2242
Copyright Statement
© 2020 The Author(s). Published by the Royal Society. All rights reserved.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/R041458/1
Subjects
01 Mathematical Sciences
02 Physical Sciences
09 Engineering
Publication Status
Published
Date Publish Online
2020-10-28