Adjustable plasmonic resonances of a gold nanotube array with a non-coaxial core

摘要

The plasmonic resonant properties of a gold nanotube array with a non-coaxial core were investigated using the finite-difference time-domain (FDTD) method. There exist two large photonic band gaps in the transmission spectra for large core offset. It is observed that the plasmonic behaviors can also be tuned by the inter-tube spacing, the size and the thickness of the nanotube with a non-coaxial core in the metallic array structure. Based on the field distribution, we deduce that the lower energy peaks of the spectra are characterized by dipole resonances, while the higher energy peaks are characterized by multipolar resonances.