講演情報
[14p-K508-9]Circularly polarized two-photon induced photoluminescence from single plasmonic nanoparticle
〇Hyoyong Ahn1, Khai Q. Le1, Tetsuya Narushima1, Junsuke Yamanishi1, Ryeong Myeong Kim2, Ki Tae Nam2, Hiromi Okamoto1 (1.Inst. for Molecular Science, 2.Seoul National Univ.)
キーワード：
chiral nanoparticles、circularly polarized luminescence、plasmonics
Materials generating circularly polarized luminescence (CPL) have been studied mostly in the category of organic dye molecules and their assemblies, or organic-inorganic hybrid systems. In these cases, the chirality of the overall luminescent system arises from the molecular chirality, for example, by using organic dyes with inherent chirality or by incorporating chiral ligands or assemblies. Recently, it has been proposed that the localized chiral electromagnetic fields of plasmonic nanostructures and metamaterials can transfer the chirality to organic dyes or quantum dots, which can be utilized for CPL generation. In the present study, we demonstrate a novel approach for “all-in-one” CPL-generating materials using chiral plasmonic nanostructures[1]. Despite being composed of a single element, the chiral Au nanoparticles are capable of simultaneously providing the photoluminescence process attributed to the electronic band structure of Au, the optical enhancement in the near-field regime based on the localized surface plasmon resonance, and the chiro-optical response arising from the nanoscale chiral structure. We found that chiral Au helicoid nanoparticles exhibit circularly polarized two-photon induced photoluminescence (TPI-PL, Fig. 1), with a very high luminescence dissymmetry factor (g-factor) of ~0.7, as single-component nanoparticles. Using electromagnetic simulations, we confirmed that the characteristic chiral gap structure of the helicoid nanoparticle is the local emission site contributing to the highly chiral light emission. The experimentally observed emission intensity and g-factor spectra were consistent with those expected from the simulation model. We believe that this work provides a new route to novel CPL-generating materials with strong dissymmetry and holds promise for various applications such as bioimaging, sensing, anti-counterfeiting, and display technologies.