Self-similar Chain of Nanocrescents with Giant Electric Field Enhancement as a Novel Plasmonic Resonator

A self-similar cascades of three nanocrescents with progressively decreasing sizes and separations were proposed in this paper. Giant electric field was obtained in this structure using 3D-FDTD simulation. The maximum E-field enhancement about 9.7^*10(4) was obtained with the polarization parallel to the axis of the chain, which is not only larger than the single crescent (6^*10(4)) but also than the self-similar chain of three spheres (about 1^*10(3)). While the maximum E-field enhancement is only about 3.1^*10(4) for the polarization perpendicular to the axis of the chain, which is larger than the single crescent and the self-similar chain of three spheres. It's obvious that the hottest spot's location and the maximum E-field value depend on the polarization of incident light. These results show that this structure as a novel plasmonic resonator holds a great promise in application of surface-enhanced Raman scattering (SERS) substrate, nanooptical detection, nanooptical antenna and other applications.