Cylindrical vector beams reveal radiationless anapole condition in a resonant state
圆柱形矢量光束揭示了共振状态下的无辐射电磁矩状态
円筒形のベクトルビームは、共鳴状態で無放射のアナポール状態を明らかにします
원통형 벡터 빔은 공진 상태에서 무방사선 아나폴 조건을 나타냅니다
Los haces vectoriales cilíndricos revelan la condición de anapolo sin radiación en un estado resonante
Les faisceaux vectoriels cylindriques révèlent une condition d'anapole sans rayonnement dans un état de résonance
Цилиндрические векторные пучки выявляют безызлучательное состояние анаполя в резонансном состоянии
Yudong Lu 卢玉东 ¹, Yi Xu 徐毅 ¹ ², Xu Ouyang 欧阳旭 ¹ ², Mingcong Xian 冼铭聪 ², Yaoyu Cao 曹耀宇 ¹, Kai Chen 陈凯 ¹, Xiangping Li 李向平 ¹
¹ Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China
中国 广州 暨南大学光子技术研究院 广东省光纤传感与通信技术重点实验室
² Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou 510632, China
中国 广州 暨南大学信息科学技术学院电子工程系
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 suppressed 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 a 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 a 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.
