Open AccessPlasmonic chirality of L-shaped nanostructure composed of two slices with different thickness
Author(s) -
Yongkai Wang,
Junchen Deng,
Gang Wang,
Tao Fu,
Qingxu Yu,
Zhongyue Zhang
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.002307
Subject(s) - chirality (physics) , materials science , circular dichroism , plasmon , polystyrene , optics , nanostructure , dichroism , monolayer , dipole , molecular physics , optoelectronics , nanotechnology , physics , chemistry , crystallography , chiral symmetry breaking , quantum mechanics , nambu–jona lasinio model , composite material , quark , polymer
A concise method is proposed to fabricate L-shaped Ag nanostructures (LSANs) for generating chirality. Prepared by glancing angle deposition, the LSAN composed of two slices with different thickness is stacked on self-assembled monolayer polystyrene nanosphere arrays by controlling substrate azimuth and deposition time. The strong optical chirality of LSANs is achieved in visible and near-IR regions by measurement. For the circular dichroism spectrum of LSANs, the intensity is enlarged, and its peaks red-shift with increasing thickness difference. When LSANs are stacked on polystyrene spheres of different diameters, enlargement and red-shift are also observed in their circular dichroism spectra with increasing thickness difference. The numerical calculations of finite element method show that the two slices composing LSAN provide cross-electric dipoles and their thickness difference provides phase difference for generating optical chirality. This study not only provides a concise and scalable method for fabricating chiral plasmonic nanostructures but also contributes to understand the knowledge of the mechanism of circular dichroism.