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Differential evolution algorithm based photonic structure design: numerical and experimental verification of subwavelength λ/5 focusing of light
Photonic structure designs based on optimization algorithms provide superior properties compared to those using intuition-based approaches. In the present study, we numerically and experimentally demonstrate subwavelength focusing of light using wavelength scale absorption-free dielectric scattering...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4967865/ https://www.ncbi.nlm.nih.gov/pubmed/27477060 http://dx.doi.org/10.1038/srep30871 |
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author | Bor, E. Turduev, M. Kurt, H. |
author_facet | Bor, E. Turduev, M. Kurt, H. |
author_sort | Bor, E. |
collection | PubMed |
description | Photonic structure designs based on optimization algorithms provide superior properties compared to those using intuition-based approaches. In the present study, we numerically and experimentally demonstrate subwavelength focusing of light using wavelength scale absorption-free dielectric scattering objects embedded in an air background. An optimization algorithm based on differential evolution integrated into the finite-difference time-domain method was applied to determine the locations of each circular dielectric object with a constant radius and refractive index. The multiobjective cost function defined inside the algorithm ensures strong focusing of light with low intensity side lobes. The temporal and spectral responses of the designed compact photonic structure provided a beam spot size in air with a full width at half maximum value of 0.19λ, where λ is the wavelength of light. The experiments were carried out in the microwave region to verify numerical findings, and very good agreement between the two approaches was found. The subwavelength light focusing is associated with a strong interference effect due to nonuniformly arranged scatterers and an irregular index gradient. Improving the focusing capability of optical elements by surpassing the diffraction limit of light is of paramount importance in optical imaging, lithography, data storage, and strong light-matter interaction. |
format | Online Article Text |
id | pubmed-4967865 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Nature Publishing Group |
record_format | MEDLINE/PubMed |
spelling | pubmed-49678652016-08-10 Differential evolution algorithm based photonic structure design: numerical and experimental verification of subwavelength λ/5 focusing of light Bor, E. Turduev, M. Kurt, H. Sci Rep Article Photonic structure designs based on optimization algorithms provide superior properties compared to those using intuition-based approaches. In the present study, we numerically and experimentally demonstrate subwavelength focusing of light using wavelength scale absorption-free dielectric scattering objects embedded in an air background. An optimization algorithm based on differential evolution integrated into the finite-difference time-domain method was applied to determine the locations of each circular dielectric object with a constant radius and refractive index. The multiobjective cost function defined inside the algorithm ensures strong focusing of light with low intensity side lobes. The temporal and spectral responses of the designed compact photonic structure provided a beam spot size in air with a full width at half maximum value of 0.19λ, where λ is the wavelength of light. The experiments were carried out in the microwave region to verify numerical findings, and very good agreement between the two approaches was found. The subwavelength light focusing is associated with a strong interference effect due to nonuniformly arranged scatterers and an irregular index gradient. Improving the focusing capability of optical elements by surpassing the diffraction limit of light is of paramount importance in optical imaging, lithography, data storage, and strong light-matter interaction. Nature Publishing Group 2016-08-01 /pmc/articles/PMC4967865/ /pubmed/27477060 http://dx.doi.org/10.1038/srep30871 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
spellingShingle | Article Bor, E. Turduev, M. Kurt, H. Differential evolution algorithm based photonic structure design: numerical and experimental verification of subwavelength λ/5 focusing of light |
title | Differential evolution algorithm based photonic structure design: numerical and experimental verification of subwavelength λ/5 focusing of light |
title_full | Differential evolution algorithm based photonic structure design: numerical and experimental verification of subwavelength λ/5 focusing of light |
title_fullStr | Differential evolution algorithm based photonic structure design: numerical and experimental verification of subwavelength λ/5 focusing of light |
title_full_unstemmed | Differential evolution algorithm based photonic structure design: numerical and experimental verification of subwavelength λ/5 focusing of light |
title_short | Differential evolution algorithm based photonic structure design: numerical and experimental verification of subwavelength λ/5 focusing of light |
title_sort | differential evolution algorithm based photonic structure design: numerical and experimental verification of subwavelength λ/5 focusing of light |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4967865/ https://www.ncbi.nlm.nih.gov/pubmed/27477060 http://dx.doi.org/10.1038/srep30871 |
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