[17a-A34-1~9] 4.1 Plasmonics and Nanophotonics

9:30 〜 10:00英語発表

[17a-A34-2] [JSAP-Optica Joint Symposia Invited Talk] Contribution of sub-radiant plasmon resonance to surface-enhanced spectroscopy

〇Tamitake Itoh¹, Yuko S. Yamamoto² (1.AIST, 2.JAIST)

キーワード：

surface-enhanced Raman scattering、surface-enhanced fluorescence、subradiant plasmon

The electromagnetic (EM) mechanisms of surface-enhanced Raman scattering (SERS) have been theoretically and experimentally verified using superradiant plasmon resonance, such as the dipole or dipole–dipole (DD) coupled plasmon resonance of small and symmetric metallic nanoparticle (NP) systems. However, higher-order plasmon resonance, such as the dipole–quadrupole (DQ) coupled plasmon resonance, which is subradiant, mainly determines the EM enhancement for large or asymmetric NP systems. Thus, clarifying the contribution of the subradiant resonance to EM enhancement is important for evaluating various plasmonic systems for SERS spectroscopy. In this presentation, the contribution of subradiant resonance to EM enhancement is explained using the spectral uncorrelation between the experimentally obtained SERS and the Rayleigh scattering spectra of silver NP dimers. Second, the radiation properties of the SERS light generated by the subradiant resonance were determined through EM calculations. Third, the importance of absorption spectroscopy in the evaluation of subradiant resonance is clarified based on quantum optics. Finally, we introduce a method to directly evaluate the EM enhancement induced by subradiant resonance using ultrafast surface-enhanced fluorescence (ultrafast SEF), which constitute the background of SERS.