[7p-A405-1~21] 3.12 Nanoscale optical science and near-field optics

△ [7p-A405-20] Generation of dip structures in transmission spectra of metal mesh devices under the focused terahertz vortex beam

〇(M1)Tomoya Okamoto¹, Yuta Mishiro¹, Shigeki Nashima¹, Takashi Kondo², Seiji Kamba², Tetsuhito Suzuki³, Yuichi Ogawa³, Katsuhiko Miyamoto^4,5, Takashige Omatsu^4,5 (1.Osaka City Univ., 2.Murata Manufacturing, Co. Ltd., 3.Kyoto Univ., 4.Chiba Univ., 5.Chiba Univ., Molecular Chirality Research Center)

Keywords:metal mesh device, vortex beam, localized multipole surface plasmon

We have investigated dip structures around anomalous terahertz (THz) transmission spectra of metal mesh devices (MMDs) under the focused terahertz vortex beams. The enhanced dip structures were clearly observed under the normally focused THz vortex beams, while the dip structures were slightly observed under the focused THz Gaussian beams. These results suggest that the enhanced dip structures of MMDs under the focused THz vortex beams would be originated from increase of coupling efficiency between multipolar plasmon mode of dip structure and incident transverse mode.