Cylindrical vector beams reveal radiationless anapole condition in a resonant state
arXiv:2104.10963 · doi:10.29026/oea.2022.210014
Abstract
Nonscattering optical anapole condition is corresponding to the excitation of radiationless field distributions in open resonators, which offers new degrees of freedom for tailoring light-matter interaction. Conventional mechanisms for achieving such a condition relies on sophisticated manipulation of electromagnetic multipolar moments of all orders to guarantee superpositions of vanished moment strengths at the same wavelength. In contrast, here we report on the excitation of optical radiationless anapole hidden in a resonant state of a Si nanoparticle utilizing tightly focused radially polarized (RP) beam. The coexistence of magnetic resonant state and anapole condition at the same wavelength further enables the triggering of resonant state by tightly focused azimuthally polarized (AP) beam whose corresponding electric multipole coefficient could be zero. As a result, high contrast inter-transition between radiationless anapole condition and ideal magnetic resonant scattering can be achieved experimentally in visible spectrum. The proposed mechanism is general which can be realized in different types of nanostructures. Our results showcase that the unique combination of structured light and structured Mie resonances could provide new degrees of freedom for tailoring light-matter interaction, which might shed new light on functional meta-optics.
11 pages, 5figures
References in corpus (6)
- Magnetic light
- High-Q Resonances Governed by the Quasi-Bound States in the Continuum in All-Dielectric Metasurfaces
- Direct amplitude-phase near-field observation of higher-order anapole states
- Anapole mediated giant photothermal nonlinearity in nanostructured silicon
- Manifestation of Extremely High-Q Pseudo-Modes in Scattering of a Bessel Light Beam by a Sphere
- Optical computation of divergence operation for vector field