Topological beam-splitting in photonic crystals
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Published version
Author(s)
Makwana, Mehul
Craster, Richard
Guenneau, Sébastien
Type
Journal Article
Abstract
We create a passive wave splitter, created purely by geometry, to engineer three-way beam splitting in electromagnetism in transverse electric and magnetic polarisation. We do so by considering arrangements of Indium Phosphide dielectric pillars in air, in particular we place several inclusions within a cell that is then extended periodically upon a square lattice. Hexagonal lattice structures are more commonly used in topological valleytronics but, as we discuss, three-way splitting is only possible using a square, or rectangular, lattice. To achieve splitting and transport around a sharp bend we use accidental, and not symmetry-induced, Dirac cones. Within each cell pillars are either arranged around a triangle or square; we demonstrate the mechanism of splitting and why it does not occur for one of the cases. The theory is developed and full scattering simulations demonstrate the effectiveness of the proposed designs.
Date Issued
2019-05-27
Date Acceptance
2019-03-21
Citation
Optics Express, 2019, 27 (11), pp.16088-16102
ISSN
1094-4087
Publisher
Optical Society of America (OSA)
Start Page
16088
End Page
16102
Journal / Book Title
Optics Express
Volume
27
Issue
11
Copyright Statement
© 2019 The Author(s). Published by The Optical Society under the terms of theCreative Commons Attribution 4.0 License. Furtherdistribution of this work must maintain attribution to the author(s) and the published article’s title, journalcitation, and DOI.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
The Leverhulme Trust
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/31163795
PII: 412847
Grant Number
EP/L024926/1
RF-2017-017/9
Subjects
Optics
0205 Optical Physics
1005 Communications Technologies
0906 Electrical and Electronic Engineering
Publication Status
Published
Coverage Spatial
United States
Date Publish Online
2019-05-22