Reducing the losses of optical metamterials

dc.contributor.advisor Costas M. Soukoulis
dc.contributor.author Fang, Anan
dc.contributor.department Department of Physics and Astronomy
dc.date 2018-08-11T14:03:53.000
dc.date.accessioned 2020-06-30T02:38:19Z
dc.date.available 2020-06-30T02:38:19Z
dc.date.copyright Fri Jan 01 00:00:00 UTC 2010
dc.date.embargo 2013-06-05
dc.date.issued 2010-01-01
dc.description.abstract <p>The field of metamaterials is driven by fascinating and far-reaching theoretical visions,</p> <p>such as perfect lenses, invisibility cloaking, and enhanced optical nonlinearities. However,</p> <p>losses have become the major obstacle towards real world applications in the optical regime.</p> <p>Reducing the losses of optical metamaterials becomes necessary and extremely important.</p> <p>In this thesis, two approaches are taken to reduce the losses. One is to construct an</p> <p>indefinite medium. Indefinite media are materials where not all the principal components of the permittivity and permeability tensors have the same sign. They do not need the resonances to achieve negative permittivity. So, the losses can be comparatively small. To obtain indefinite media, three-dimensional (3D) optical metallic nanowire media with different structures are designed. They are numerically demonstrated that they are homogeneous effective indefinite anisotropic media by showing that their dispersion relations are hyperbolic. Negative group refraction and pseudo focusing are observed.</p> <p>Another approach is to incorporate gain into metamaterial nanostructures. The nonlinearity</p> <p>of gain is included by a generic four-level atomic model. A computational scheme</p> <p>is presented, which allows for a self-consistent treatment of a dispersive metallic photonic</p> <p>metamaterial coupled to a gain material incorporated into the nanostructure using the finite difference time-domain (FDTD) method. The loss compensations with gain are done for various structures, from 2D simplified models to 3D realistic structures. Results show the losses of optical metamaterials can be effectively compensated by gain. The effective gain coefficient of the combined system can be much larger than the bulk gain counterpart, due to the strong local-field enhancement.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/11807/
dc.identifier.articleid 2795
dc.identifier.contextkey 2807993
dc.identifier.doi https://doi.org/10.31274/etd-180810-210
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/11807
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/26013
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/11807/Fang_iastate_0097E_11603.pdf|||Fri Jan 14 18:59:05 UTC 2022
dc.subject.disciplines Physics
dc.subject.keywords FDTD
dc.subject.keywords gain
dc.subject.keywords lasing
dc.subject.keywords loss compensation
dc.subject.keywords metamaterial
dc.subject.keywords negative-index material
dc.title Reducing the losses of optical metamterials
dc.type dissertation
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 4a05cd4d-8749-4cff-96b1-32eca381d930
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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