Fano control of plasmonic double-resonant systems

Download
2021-2-12
Postacı, Selen
The nonlinear response of plasmonic nanostructures can be enhanced as a result of the localization of the incident field into nm-size regions, called hot spots. The Raman signal of a molecule can be enhanced by adsorbing it to the surface of a plasmonic structure. However, the hot spot enhancement is limited with the modification of the vibrational modes, the breakdown of the molecule, and transition to the tunneling regime. The analytical treatment that is presented in this study aims to circumvent these limitations by introducing the nonlinear path interference effects. Coupling a quantum emitter to the double-resonant metal nanostructure yields to path interference, enabling the further manipulation of the SERS signal. The results denote that an extra enhancement of 100-1000 factors can occur, which does not alter the existing hot spot field intensities. Besides the analytical results, 3 Dimensional solutions of Maxwell equations are also utilized in order to understand the effects of retardation on the system. In the second part, the second harmonic response of a double-resonant metal nanostructure is studied with the coupling of a quantum emitter. The quantum emitter is driven with a source where changing the pump strength enables the modification of the second converted field intensity. It is observed that as the nonlinear response of the system is enhanced, the nonclassicality measure also shows an increase. This result indicates that pumping the quantum emitter with a source provides the opportunity to modify the nonlinear response via Fano type resonances in plasmonic structures.

Suggestions

Silent enhancement of SERS signa without increasing hot spot intensities
Postaci, Selen; Yildiz, Bilge Can; Bek, Alpan; TAŞGIN, MEHMET EMRE (2018-10-01)
Plasmonic nanostructures enhance nonlinear response, such as surface enhanced Raman scattering (SERS), by localizing the incident field into hot spots. The localized hot spot field can be enhanced even further when linear Fano resonances take place in a double resonance scheme. However, hot spot enhancement is limited with the modification of the vibrational modes, the breakdown of the molecule, and the tunneling regime. Here, we present a method which can circumvent these limitations. Our analytical model ...
Fano Resonances in the Linear and Nonlinear Plasmonic Response
Taşgın, Mehmet Emre; Bek, Alpan; Postacı, Selen (Springer, 2018-01-01)
Fano resonances manifest novel phenomena both in linear and nonlinear response of plasmonic nanomaterials. They can extend the lifetime of plasmonic excitations, enabling the operation of nanolasers, or they can increase the fluorescence of quantum emitters. They also provide control over nonlinear optical processes such as second harmonic generation and surface enhanced Raman scattering. Fano resonances can both enhance and suppress nonlinear response. Interference of two or more absorption/conversion path...
Fano-control of down-conversion in a nonlinear crystal via plasmonic-quantum emitter hybrid structures
Artvin, Zafer; Gunay, Mehmet; Bek, Alpan; TAŞGIN, MEHMET EMRE (The Optical Society, 2020-12-01)
Control of the nonlinear response of nanostructures via path interference effects, i.e., Fano resonances, has been studied extensively. In such studies, a frequency conversion process takes place near a hot spot. Here, we study the case where the frequency conversion process takes place along the body of a nonlinear crystal. Metal nanoparticle-quantum emitter dimers control the down-conversion process, taking place throughout the crystal body, via introducing interfering conversion paths. Dimers behave as i...
Fano enhancement of unlocalized nonlinear optical processes
Günay, Mehmet; Cicek, Ahmet; Korozlu, Nurettin; Bek, Alpan; TAŞGIN, MEHMET EMRE (2021-12-15)
Field localization boosts nonlinear optical processes at the hot spots of metal nanostructures. Fano resonances can further enhance these "local"processes taking place at the hot spots. However, in conventional nonlinear materials, the frequency conversion takes place along the entire crystal body. That is, the conversion process is "unlocalized."The path interference (Fano resonance) schemes developed for localized processes become useless in such materials. Here, we develop Fano enhancement schemes for un...
Higgs, chargino and neutralino mass spectra in RPV U(1)' model
SELBUZ, LEVENT; Frank, M.; Turan, İsmail (2017-11-01)
We examine the sensitivity of the particle spectrum to the parameters of the U(1)'-extended MSSM with R-parity violation. This model provides a simultaneous solution to both the mu-problem and the proton decay problem which plague the MSSM. We focus on variations of neutralino, chargino and Higgs boson masses in various lepton number violations couplings, scanning over all the space to find allowed regions of the parameter space consistent with the experimental constraints for these masses.
Citation Formats
S. Postacı, “Fano control of plasmonic double-resonant systems,” Ph.D. - Doctoral Program, Middle East Technical University, 2021.