Fano共振效应是量子体系中分立态能级和连续态能带相互重叠,在光谱中表现出非对称线型的共振散射现象,最初由U. Fano经过严格的理论验证得到。近年来,在表面等离激元结构体系中也陆续发现了等离激元Fano共振现象,它是由结构支持的辐射模式和非辐射模式相互作用产生的。等离激元Fano共振具有光谱线宽较窄、辐射损耗小以及能够将入射场局限在结构表面并使近场显著增强等优势,因此成为了纳米光子学中的研究热点。在支持Fano共振激发的等离激元结构中,类圆盘结构具有较宽的辐射模式线宽,可以和结构支持的一个或多个弱辐射模式耦合,因此可以有效激发单一或多重等离激元Fano共振,并能够实现对Fano共振的有效调制。此外,类圆盘纳米结构体系在拥有高度几何对称性或规则的多个体数量条件下,仍然可以激发高强度的等离激元Fano共振模式,这进一步拓展了Fano共振纳米结构的设计思路。我们总结了近年来激发等离激元Fano共振模式的类圆盘结构组成的体系,其中包括单一圆盘结构、异类二聚体圆盘结构和多聚体类圆盘结构等,并对这些体系支持的Fano共振的产生机理和激发方式进行了详细的分析。另外,对支持等离激元Fano共振的类圆盘纳米结构的应用也进行了简单的论述。

Fano resonance, theoretically explained by U. Fano, is a type of resonant scattering phenomenon in the quantum system that results from interference between discrete and continuous state energy, and gives rise to an asymmetrical line-shape. In recent years, plasmonic Fano resonance has been found in the plasmonic structure system, which is produced by the interaction between the superradiation mode and the subradiation mode supported by the structure. Because the Fano resonance has narrow frequency linewidth, weak radiative losses, and strong near-field enhancement on the surface of structures, it has attracted much attention in the field of photonics. The disk-like structure which has the ability of supporting wider superradiation linewidth can couple with one or more subradiation patterns supported by the structure to excite and modulate single or multiple Fano resonances effectively. Moreover, the disk-like nanostructured systems can still excite high-intensity plasmonic Fano resonance under the case of highly geometric symmetry or regularly multi-individual composition, which can further expand the design of Fano resonant nanostructures. In this paper, we summarized the disk-like Fano resonance nanostructure, including single disk structure, heterogeneous dimer disk structure and multipolymer disk structure, and presented the mechanism and excitation of the plasmonic Fano resonance. In addition, we also briefly discussed the applications of disk-like Fano resonance nanostructure.