Silent enhancement of SERS signa without increasing hot spot intensities

Postaci, Selen
Yildiz, Bilge Can
Bek, Alpan
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 and solutions of 3D Maxwell equations show that: enhancement due to the localized field can be multiplied by a factor of 10(2)-10(3). Moreover, this can be performed without increasing the hot spot intensity which also avoids the modification of the Raman modes. Unlike linear Fano resonances, here, we create a path interference in the nonlinear response. We demonstrate on a single equation that enhancement takes place due to cancellation of the contributing terms in the denominator of the SERS response. Our method can be implemented on an atomic force microscope tip, decorated (or "contaminated") with appropriate quantum emitters.


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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 l...
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In this study, our aim is to fabricate and characterize efficient substrates of surface enhanced Raman spectroscopy (SERS) utilizing the field enhancement due to hot spots made by recently developed method of laser induced periodic surface structuring (LIPSS). LIPSS is a cost-effective technique for rapid processing of almost any materials compared to conventional lithography methods. Coating of a thin silver film on LIPSS applied substrate surface provides to observe the localized surface plasmon effect fo...
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The combined-field integral equation (CFIE) is employed to formulate the electromagnetic scattering and radiation problems of composite geometries with coexisting open and closed conducting surfaces. Conventional formulations of these problems with the electric-field integral equation (EFIE) lead to inefficient solutions due to the ill-conditioning of the matrix equations and the internal-resonance problems. The hybrid CFIE-EFIE technique introduced in this paper, based on the application of the CRE on the ...
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Hot spots are defined as nanostructures of noble metal able to locally enhance the electromagnetic field of several orders of magnitude and to confine this effect to a region for several orders of magnitude smaller than the light wavelength. Hot spots are particularly important for the surface enhanced Raman spectroscopy applications, in which the field enhancement is used to amplify the usually weak Raman scattering signal. The hot spots are mostly generated between two or more plasmonic nanostructures sep...
Citation Formats
S. Postaci, B. C. Yildiz, A. Bek, and M. E. TAŞGIN, “Silent enhancement of SERS signa without increasing hot spot intensities,” NANOPHOTONICS, pp. 1687–1695, 2018, Accessed: 00, 2020. [Online]. Available: