Ayas S.Güner, H.Türker, B.Ekiz, O. O.Dirisaglik, F.Okyay, Ali KemalDâna, A.2016-02-082016-02-082012-07-301936-0851http://hdl.handle.net/11693/21355Plasmonic metamaterials allow confinement of light to deep subwavelength dimensions, while allowing for the tailoring of dispersion and electromagnetic mode density to enhance specific photonic properties. Optical resonances of plasmonic molecules have been extensively investigated; however, benefits of strong coupling of dimers have been overlooked. Here, we construct a plasmonic meta-surface through coupling of diatomic plasmonic molecules which contain a heavy and light meta-atom. Presence and coupling of two distinct types of localized modes in the plasmonic molecule allow formation and engineering of a rich band structure in a seemingly simple and common geometry, resulting in a broadband and quasi-omni-directional meta-surface. Surface-enhanced Raman scattering benefits from the simultaneous presence of plasmonic resonances at the excitation and scattering frequencies, and by proper design of the band structure to satisfy this condition, highly repeatable and spatially uniform Raman enhancement is demonstrated. On the basis of calculations of the field enhancement distribution within a unit cell, spatial uniformity of the enhancement at the nanoscale is discussed. Raman scattering constitutes an example of nonlinear optical processes, where the wavelength conversion during scattering may be viewed as a photonic transition between the bands of the meta-material.EnglishCoupled plasmonic modesMetamaterialsPlasmonicsSurface-enhanced Raman spectroscopyBasis of calculationElectromagnetic modesField enhancementLocalized modesNano scaleNonlinear optical processOptical resonancePhotonic propertiesPlasmonicPlasmonic metamaterialsPlasmonicsProper designRaman enhancementScattering frequencySpatial uniformityStrong couplingSub-wavelengthSurface enhanced Raman scattering (SERS)Surface enhanced Raman spectroscopyUnit cellsBand structureMetamaterialsMoleculesQuantum opticsRaman scatteringRaman spectroscopyPlasmonsMetal nanoparticleChemical modelChemical structureChemistryComputer simulationLightMaterials testingMethodologyRadiation scatteringSurface plasmon resonanceUltrastructureComputer simulationLightMaterials testingMetal nanoparticlesMolecularRadiationSurface plasmon resonanceArticle10.1021/nn301665a