12-01-2012, 01:03 PM
Manipulating optical rotation in extraordinary transmission by hybrid
plasmonic excitations
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Since the pioneering work of Ebbesen et al. of extraordinary
optical transmission EOT,1 the interaction between
the light and the surface plasmon excitation in metallic
micro/nanostructures acquires a growing attention of research,
not only for the fascinating fundamental physics but
also for its wide potential applications in photonic devices,
sensors, and so on.2–4 Tremendous studies have been carried
out to expose the relationship between the surface plasmon
polartion SPP and EOT phenomenon.5–8 Nevertheless, besides
the enhanced transmission intensity, polarization state
is another important characteristic in optics. Researchers
have found the strong polarization dependence related to the
localized surface plasmon LSP excitation arising from the
holes shape resonance.9–11 However, most of these LSP
modes are relative simplex, in which the enhanced transmissions
are always limited in one polarization state lacking
variability and controllability. From this point, it is difficult
to effectively change the polarization states and control the
optical rotation in those systems.
In this letter, we report an experimental realization of
manipulating the polarization state of the light and achieving
giant optical rotation in near infrared wavelength by a nanometer
thickness structure. Actually, using chiral structures or
metamaterials to manipulate the optical polarization has arrested
considerable interest in the nearest years.12–19 Unfortunately,
these designs usually demand complex nanostructures,
which are relative difficulty to fabricate for the
response in optical region. However, for the proposed structure,
only simple L-shaped holes are introduced in the single
metallic film, which are much easier in fabrication even in
the nanoscale. Moreover, it combines the advantageous of
the SPP enhanced transmission and LSP assisted optical rotation,
suggesting potential applications in micro-optical controller
or devices.