Dielectric Sphere Oligomers as Optical Nanoantenna for Circularly Polarized Light.
Shintaro Ogura, Hidemasa Negoro, Izzah Machfuudzoh, Zac Thollar, Tatsuki Hinamoto, F Javier García de Abajo, Hiroshi Sugimoto, Minoru Fujii, Takumi Sannomiya
Author Information
Shintaro Ogura: Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
Hidemasa Negoro: Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan.
Izzah Machfuudzoh: Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
Zac Thollar: Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
Tatsuki Hinamoto: Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan. ORCID
F Javier García de Abajo: ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain. ORCID
Hiroshi Sugimoto: Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan. ORCID
Minoru Fujii: Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan.
Takumi Sannomiya: Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan. ORCID
Control of circularly polarized light (CPL) is important for next-generation optical communications as well as for investigating the optical properties of materials. In this study, we explore dielectric-sphere oligomers for chiral nanoantenna applications, leveraging the cathodoluminescence (CL) technique, which employs accelerated free electrons for excitation and allows mapping the optical response on the nanoscale. For a certain particle-dimers configuration, one of the spheres becomes responsible for the left-handed circular polarization of the emitted light, while right-handed circular polarization is selectively yielded when the other sphere is excited by the electron beam. Similar patterns are also observed in trimers. These phenomena are understood in terms of optical coupling between the electric and magnetic modes hosted by the dielectric spheres. Our research not only expands the understanding of CPL generation mechanisms in dielectric-sphere oligomer antennas but also underscores the potential of such structures in optical applications. We further highlight the utility of CL as a powerful analytical tool for investigating the optical properties of nanoscale structures as well as the potential of electron beams for light generation with switchable CPL parities.
References
Nature. 2017 Jan 25;541(7638):473-480
[PMID: 28128249]
Phys Rev Lett. 2009 Mar 20;102(11):113902
[PMID: 19392202]
