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The Design And Fabrication Of Surface Enhanced Raman Spectroscopy(SERS) Substrate With Double Resonance

Posted on:2018-04-30Degree:MasterType:Thesis
Country:ChinaCandidate:Z H LiuFull Text:PDF
GTID:2381330596490135Subject:Biomedical engineering
Abstract/Summary:PDF Full Text Request
Creating plasmonic nanostructures with controllable Fano resonances is of great interest for a number of important applications including metamaterials and biosensors.Realizing double Fano resonances is challenging but may become favorable to the applications such as surface enhanced Raman scattering?SERS?and second harmonic generation?SHG?.Here we have developed plasmonic structures consisted of a nanostructure array?the round ring,triangular ring or the circular hole array?and a metallic film separated by a dielectric insulator,that is the nanostructure-insulator-film?NIF?.Firstly,highly controllable double Fano resonances have been generated by the NIF constructed by nanoring arrays.The double Fano resonances are realized by the strong plasmonic coupling between the localized surface plasmon resonance?LSPR?mode of the nanoring array and the cavity modes of the nanocavity,and consequently exhibit large electric field enhancements at both the resonant frequencies.The resonance wavelength,the linewidth and the wavelength separation of double Fano resonances can be well tailored by altering the parameters of the top array pattern or the cavity length of the structure.Typical NIFs designed by the simulation are successfully fabricated,where the double resonances are reproduced and with which the results of the simulation are validated.A far-field coupling model was developed to explain the coupling phenomena and design the NIFs with one typical resonance.Next,in the NIF constructued by triangular ring array,the dark mode of the nanoarray was efficiently stimulated and the electric field enhancement was significantly amplified though its coupling with cavity mode.Last,when VO2 or piezoelectric material is integrated into the NIF,the active tunability of nanoarray's LSPR or nanocavity's cavity mode are realized.Based on these strategies,two types of plasmonic structures with active modulatable double resonances are designed.The coupling between LSPR and cavity modes explored in our work paves the way for the designing and application of such double resonance plasmonic devices.
Keywords/Search Tags:Surface enhanced Raman spectroscopy, Plasmonic, Double resonance, Dark mode, Active plasmonics
PDF Full Text Request
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