[14a-K506-1~10] 3.11 Nanoscale optical science and near-field optics

11:00 AM - 11:15 AM JST(2:00 AM - 2:15 AM UTC)

[14a-K506-8] Chiroptical response of isotropic plasmonic particles having a chiral arrangement

〇Tomoya Oshikiri^1,2, Yasutaka Matsuo², Hiromasa Niinomi¹, Masaru Nakagawa¹ (1.Tohoku Univ., 2.Hokkaido Univ.)

Keywords:

Chirality,Plasmon,Modal coupling

We demonstrate that collective mode formation under modal coupling between localized surface plasmon resonances (LSPRs) with a chiral arrangement and Fabry–Pérot (FP) nanocavity modes can induce chiroptical responses. We fabricated a cluster of isotropic gold nanodisks with a chiral arrangement (gold nano-windmills, Au-NWs) on the FP nanocavities of TiO₂ and Au film. The differential absorption of the Au-NWs coupled with the FP nanocavities under left- and right-handed circularly polarized light irradiations in the far field was significantly enhanced compared with the differential absorption without the FP nanocavities. Far- and near-field analyses by numerical simulation revealed that the Au-NWs coupled with the FP nanocavities formed a collective mode in the near field, and the collective mode represented the chiroptical response in the far field.