umu.sePublications
Change search
ReferencesLink to record
Permanent link

Direct link
Topology and shape optimization of plasmonic nano-antennas
Umeå University, Faculty of Science and Technology, Department of Computing Science.
Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
2015 (English)In: Computer Methods in Applied Mechanics and Engineering, ISSN 0045-7825, E-ISSN 1879-2138, Vol. 293, 155-169 p.Article in journal (Refereed) Published
Abstract [en]

Metallic nano-antennas are devices used to concentrate the energy in light into regions that are much smaller than the wavelength. These structures are currently used to develop new measurement and printing techniques, such as optical microscopy with sub-wavelength resolution, and high-resolution lithography. Here, we analyze and design a nano-antenna in a two-dimensional setting with the source being a planar TE-polarized wave. The design problem is to place silver and air in a pre-specified design region to maximize the electric energy in a small given target region. At optical frequencies silver exhibits extreme dielectric properties, having permittivity with a negative real part. We prove existence and uniqueness of solutions to the governing nonstandard Helmholtz equation with absorbing boundary conditions. To solve the design optimization problem, we develop a two-stage procedure. The first stage uses a material distribution parameterization and aims at finding a conceptual design without imposing any a priori information about the number of shapes of components comprising the nano-antenna. The second design stage uses a domain variation approach and aims at finding a precise shape. Both of the above design problems are formulated as non-linear mathematical programming problems that are solved using the method of moving asymptotes. The final designs perform very well and the electric energy in the target region is several orders of magnitude larger than when there is only air in the design region. The performance of the optimized designs is verified with a high order interior penalty method.

Place, publisher, year, edition, pages
Elsevier, 2015. Vol. 293, 155-169 p.
Keyword [en]
Nano-antennas, Plasmonics, Topology optimization, Shape optimization
National Category
Mechanical Engineering Mathematics
Identifiers
URN: urn:nbn:se:umu:diva-109945DOI: 10.1016/j.cma.2015.04.011ISI: 000361475900008OAI: oai:DiVA.org:umu-109945DiVA: diva2:860929
Available from: 2015-10-14 Created: 2015-10-09 Last updated: 2015-10-14Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Wadbro, EddieEngström, Christian
By organisation
Department of Computing ScienceDepartment of Mathematics and Mathematical Statistics
In the same journal
Computer Methods in Applied Mechanics and Engineering
Mechanical EngineeringMathematics

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 38 hits
ReferencesLink to record
Permanent link

Direct link