title: Excitation of plasmon toroidal mode at optical frequencies by angle-resolved reflection.
abstract: Plasmon toroidal mode is a unique electromagnetic resonance that cannot be expanded by general electronic or magnetic multipoles. Usually, this mode excitation needs complicated nanostructures, which is a challenge for sample fabrications, especially for nanodesigns with optical resonant frequencies. In this work, we designed a circular V-groove array and studied its toroidal-mode excitation by angle-resolved reflection experimentally and numerically. Our results show that a plasmon toroidal mode around wavelength 700 nm can be excited in this simple nanostructure for incident angles larger than 20°. Compared to reported papers, our design can realize the optical excitation of plasmon toroidal mode, which is useful in high-sensitivity plasmon sensors.
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Li
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Renchao
authors.initials: R
authors.lastname: Jin
authors.forename: Qianjin
authors.initials: Q
authors.lastname: Wang
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.forename: Zhenggao
authors.initials: Z
authors.lastname: Dong