Open AccessSlot antenna as a bound charge oscillator
Author(s) -
Jong-Ho Choe,
Ji-Hun Kang,
DaiSik Kim,
Q-Han Park
Publication year - 2012
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.20.006521
Subject(s) - scattering , physics , bound state , antenna (radio) , resonance (particle physics) , radiative transfer , charge (physics) , optics , light scattering , computational physics , atomic physics , quantum mechanics , telecommunications , computer science
We study the scattering properties of an optical slot antenna formed from a narrow rectangular hole in a metal film. We show that slot antennas can be modeled as bound charge oscillators mediating resonant light scattering. A simple closed-form expression for the scattering spectrum of a slot antenna is obtained that reveals the nature of a bound charge oscillator and also the effect of a substrate. We find that the spectral width of scattering resonance is dominated by a radiative damping caused by the Abraham-Lorentz force acting on a bound charge. The bound charge oscillator model provides not only an intuitive physical picture for the scattering of an optical slot antenna but also reasonable numerical agreements with rigorous calculations using the finite-difference time-domain method.