Optics Communications ( IF 2.125 ) Pub Date : 2020-01-07 , DOI: 10.1016/j.optcom.2020.125241 Zhongyu Wang, Jun Dong, Wei Gao, Qingyan Han, Minghan Qi, Jianxia Qi, Qijing Wang, Yongkai Wang
Circular dichroism (CD) is widely used in bio-sensing, pharmaceuticals, and molecular chemistry. Symmetry breaking is an important method of achieving CD signals. However, the relationship between the magnitude of CD and symmetry breaking remains unclear. In this study, we introduce nanorods into symmetric nanostructures comprising vertical Q-shaped nanostructure arrays (VQNAs) to prove the relativity of the symmetry breaking. The numerical simulations results show that the CD spectra of VQNAs present four modes in the visible spectrum. The coupling between nanorods differs under left- and right-handed circular polarized illuminations, leading to the production of the CD. The CD magnitude is not monotonic when the parameters of VQNAs change, and it is the largest for the structure at an appropriate scale. Besides, VQNAs have stable optical properties. Results can help to understand more deeply the CD mechanism produced by symmetry breaking, and design chiral plasmonic nanostructures.