Nowadays plasmonics is rapidly developing areas from fundamental studies to
more application driven research. This dissertation contains three different research
topics on plasmonics. In the first research topic, by modulating the zone width of a
plasmonic zone plate, we demonstrate that a beam focused by a proposed plasmonic
zone plate lens can be achieved with higher intensity and smaller spot size than the
diffraction-limited conventional zone plate lens. This sub-diffraction focusing capability
is attributed to extraordinary optical transmission, which is explained by the complex
propagation constant in the zone regions afforded by higher refractive index dielectric
layer and surface plasmons. On the other hand, the resulted diffraction efficiency of this
device is relatively low. By introducing a metal/dielectric multilayered zone plate, we
present higher field enhancement at the focal point. This higher field enhancement
originates not only from surface plasmon polaritons-assisted diffraction process along
the propagation direction of the incident light (longitude mode), but also from multiple
scattering and coupling of surface plasmons along the metal/dielectric interface
(transverse mode). In the second research topic, we suggest a novel concept of SERS-active
substrate applications. The surface-enhanced Raman scattering enhancement factor
supported by gap surface plasmon polaritons is introduced. Due to higher effective
refractive index induced by gap surface plasmon polaritons in the spacer region between
two metal plates, incident light tends to localize itself mostly in the medium with higher
refractive index than its adjacent ones and thereby the lights can confine with larger field
enhancement.
In the last research topic, we offer a simple structure in which a gold dipole
antenna is formed on the SiC substrate. Surface phonon polaritons, counterparts of
surface plasmon polaritons in the mid-infrared frequencies, are developed. Due to the
synergistic action between the conventional dipole antenna coupling and the resonant
excitation of surface phonon polaritons, strong field enhancement in the gap region of
dipole antenna is attained.
Most of research topics above are expected to find promising applications such
as maskless nanolithography, high resolution scanning optical microscopy, optical data
storage, optical antenna, SERS-active substrate, bio-molecular sensing and highly
sensitive photo-detectors.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-08-897 |
| Date | 2009 August 1900 |
| Creators | Kim, Hyun Chul |
| Contributors | Cheng, Mosong, Cheng, Xing |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | application/pdf |
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