Open AccessGiant plasmonic circular dichroism in Ag staircase nanostructures
Author(s) -
Chunrui Han,
Ho Ming Dick Leung,
Che Ting Chan,
Wing Yim Tam
Publication year - 2015
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.033065
Subject(s) - circular dichroism , antiparallel (mathematics) , dipole , nanostructure , plasmon , materials science , electric dipole moment , optics , magnetic moment , magnetic dipole , transition dipole moment , condensed matter physics , molecular physics , physics , optoelectronics , nanotechnology , magnetic field , chemistry , crystallography , quantum mechanics
We demonstrate large circular dichroism (CD) in the visible range resulting from electromagnetic couplings in three-dimensional Ag staircase nanostructures. Analytical calculations using effective constitutive parameters show that the CD originates from chiral resonances of the staircase in which the induced magnetic dipole moment has components parallel or antiparallel to the induced electric dipole moment. The strength of the coupling as well as the CD can be tuned by varying the configuration (e.g. the strip width) of staircase nanostructure. More importantly we are able to realize such chiral resonances with large CD in the visible range in topologically similar chiral nanostructures fabricated using a simple shadowing vapor deposition method. Our simple staircase model demonstrates the effect of couplings between electric and magnetic dipole moments in producing large chiral responses in 3D nanostructures and can enhance the understanding of hybrid chiral optical systems.