[8p-N204-1~18] 3.11 Nanoscale optical science and near-field optics

4:00 PM - 4:15 PM JST(7:00 AM - 7:15 AM UTC)

[8p-N204-10] Observation of electromagnetic coupling between radiant or subradiant plasmon and dye molecular exciton using ultrafast surface-enhanced fluorescence

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

Keywords:

subradiant plasmon,ultrafast surface enhanced fluorescence

In the nanogaps between gold and silver nanoparticle dimers, the electric field enhancement due to plasmon resonance increases the fluorescence rate by the factor of < 10⁵, exceeding the vibrational relaxation rate. These gaps are called hot spots (HSs), and this phenomenon is called ultrafast surface-enhanced fluorescence (ultrafast SEF). In HS, plasmons and excitons of a small number of dye molecules may form a strong coupling system. To observe this strong coupling, the Rayleigh scattering spectral change of radiant plasmons has been used, but systems in which subradiant plasmons, which cannot be observed by Rayleigh scattering, dominate the strong coupling are more commonly present. Therefore, we attempted to observe the spectral change due to strong coupling using ultrafast SEF, which allows observation of subradiant plasmons.