用于表面增强拉曼散射应用的全介质纳米天线的光学非偶极子模式设计。

Design of optical anapole modes of all-dielectric nanoantennas for SERS applications.

作者信息

Wang Debao, Lv Jingwei, Wang Jianxin, Ren Yanru, Yu Ying, Li Wei, Chu Paul K, Liu Chao

出版信息

Appl Opt. 2023 Jul 10;62(20):5538-5546. doi: 10.1364/AO.494145.

Abstract

To obtain large electric field enhancement while mitigating material losses, an all-dielectric nanoantenna composed of a heptamer and nanocubes is designed and analyzed. A numerical simulation by the finite element method reveals that the nanoantenna achieves the optical electric anapole modes, thereby significantly enhancing the coupling between different dielectrics to further improve the near-field enhancement and spontaneous radiation. Field enhancement factors |/ | of 3,563 and 5,395 (AM1 and AM2) and a Purcell factor of 3,872 are observed in the wavelength range between 350 and 800 nm. This nanoantenna has promising potential in applications involving surface-enhanced Raman scattering and nonlinearities due to its low cost and excellent compatibility.

摘要

为了在减轻材料损耗的同时获得大的电场增强，设计并分析了一种由七聚体和纳米立方体组成的全介质纳米天线。有限元方法的数值模拟表明，该纳米天线实现了光电无偶极子模式，从而显著增强了不同电介质之间的耦合，进一步提高了近场增强和自发辐射。在350至800纳米的波长范围内，观察到场增强因子|/|分别为3563和5395（AM1和AM2），珀塞尔因子为3872。这种纳米天线因其低成本和优异的兼容性，在表面增强拉曼散射和非线性等应用中具有广阔的前景。