Microscopic origin of surface-plasmon radiation in plasmonic band-gap nanostructures.
We report spatial domain measurements of the damping of surface-plasmon excitations in metal films with periodic nanohole arrays. The measurements reveal a short coherent propagation length of a few microm inside nanohole arrays, consistent with delays of about 10 fs in ultrafast transmission experiments. This implies that the transmission spectra of the entire plasmonic band-gap structure are homogeneously broadened by radiative damping of surface-plasmon excitations. We show that a Rayleigh-like scattering of surface plasmons by the periodic hole array is the microscopic origin of this damping, allowing the reradiation rate to be controlled.
Kim
D S
DS
School of Physics, Seoul National University, Seoul 151-742, Korea.
Hohng
S C
SC
Malyarchuk
V
V
Yoon
Y C
YC
Ahn
Y H
YH
Yee
K J
KJ
Park
J W
JW
Kim
J
J
Park
Q H
QH
Lienau
C
C