Time- and space-resolved study of spoof localized surface plasmon using terahertz near field spectroscopy

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K17529
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Optical engineering, Photon science
• Research Institution: Kyoto University
• Principal Investigator: Arikawa Takashi 京都大学, 理学研究科, 助教 (70598490)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: テラヘルツ / プラズモニクス / 近接場 / メタマテリアル / 擬似局在表面プラズモン

Outline of Final Research Achievements

Spoof localized surface plasmon is studied as a promising tool to overcome the poor spatial resolution of terahertz spectroscopy due to the diffraction limit. The basic properties predicted from the theory are experimentally confirmed and controlled by changing the geometry parameters of the metallic structure. Also, vortex beam, i.e., light with orbital angular momentum is used to selectively excite multipolar modes of spoof localized surface plasmon. As a result, selection rules governed by the conservation of the total angular momentum between light and spoof localized surface plasmon are confirmed. This is the same selection rules known for localized surface plasmon in visible/infrared region. These results show spoof localized surface plasmon would allow us to realize spatial resolution beyond the diffraction limit with ultrahigh sensitivity, as realized in the visible/infrared plasmonics.

Free Research Field

テラヘルツ分光

Academic Significance and Societal Importance of the Research Achievements

擬似局在表面プラズモンを利用することにより、テラヘルツ帯においても可視域プラズモニクスの莫大な研究の蓄積を継承し、高分解能、高感度測定を実現できる可能性がある。本研究による擬似局在表面プラズモンの基礎特性の理解はこのような技術的発展の基礎となるものであると言える。