Accurate Modeling of Dark-Field Scattering Spectra of Plasmonic Nanostructures.
Dark-field microscopy is a widely used tool for measuring the optical resonance of plasmonic nanostructures. However, current numerical methods for simulating the dark-field scattering spectra were carried out with plane wave illumination either at normal incidence or at an oblique angle from one direction. In actual experiments, light is focused onto the sample through an annular ring within a range of glancing angles. In this paper, we present a theoretical model capable of accurately simulating the dark-field light source with an annular ring. Simulations correctly reproduce a counterintuitive blue shift in the scattering spectra from gold nanodisks with a diameter beyond 140 nm. We believe that our proposed simulation method can be potentially applied as a general tool capable of simulating the dark-field scattering spectra of plasmonic nanostructures as well as other dielectric nanostructures with sizes beyond the quasi-static limit.
Nanophotonic Laboratory, Department of Physics, Nanjing University of Science and Technology , Nanjing 210094, China.|Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371.
Liyong
L
Jiang
Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371.
Tingting
T
Yin
Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research) , 3 Research Link, Singapore 117602.
Zhaogang
Z
Dong
School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371.
Mingyi
M
Liao
Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research) , 3 Research Link, Singapore 117602.
Shawn J
SJ
Tan
Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research) , 3 Research Link, Singapore 117602.
Xiao Ming
XM
Goh
School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371.
David
D
Allioux
School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371.
Hailong
H
Hu
Nanophotonic Laboratory, Department of Physics, Nanjing University of Science and Technology , Nanjing 210094, China.
Xiangyin
X
Li
Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research) , 3 Research Link, Singapore 117602.|Singapore University of Technology and Design , 8 Somapah Road, Singapore 487372.
Joel K W
JK
Yang
Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371.|School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371.
Zexiang
Z
Shen
dark-field scattering spectra; gold nanodisks; localized surface plasmon resonance; quasi-static limit; retardation effects