Plasmonic properties and the related novel applications are studied on various
types of metallic nano-structures in one, two, or three dimensions. For 1D nanostructure,
the motion of free electrons in a metal-film with nanoscale thickness is confined in
its normal dimension and free in the other two. Describing the free-electron motion at
metal-dielectric surfaces, surface plasmon polariton (SPP) is an elementary excitation
of such motions and is well known. When further perforated with periodic array of
holes, periodicity will introduce degeneracy, incur energy-level splitting, and facilitate
the coupling between free-space photon and SPP. We applied this concept to achieve
a plasmonic perfect absorber. The experimentally observed reflection dip splitting
is qualitatively explained by a perturbation theory based on the above concept. If
confined in 2D, the nanostructures become nanowires that intrigue a broad range of
research interests. We performed various studies on the resonance and propagation
of metal nanowires with different materials, cross-sectional shapes and form factors,
in passive or active medium, in support of corresponding experimental works. Finite-
Difference Time-Domain (FDTD) simulations show that simulated results agrees well
with experiments and makes fundamental mode analysis possible. Confined in 3D,
the electron motions in a single metal nanoparticle (NP) leads to localized surface
plasmon resonance (LSPR) that enables another novel and important application:
plasmon-heating. By exciting the LSPR of a gold particle embedded in liquid, the
excited plasmon will decay into heat in the particle and will heat up the surrounding
liquid eventually. With sufficient exciting optical intensity, the heat transfer from NP
to liquid will undergo an explosive process and make a vapor envelop: nanobubble.
We characterized the size, pressure and temperature of the nanobubble by a simple
model relying on Mie calculations and continuous medium assumption. A novel
effective medium method is also developed to replace the role of Mie calculations.
The characterized temperature is in excellent agreement with that by Raman scattering.
If fabricated in an ordered cluster, NPs exhibit double-resonance features and
the double Fano-resonant structure is demonstrated to most enhance the four-wave
mixing efficiency.
| Identifer | oai:union.ndltd.org:RICE/oai:scholarship.rice.edu:1911/72071 |
| Date | 16 September 2013 |
| Creators | Zhen, Yurong |
| Contributors | Nordlander, Peter J. |
| Source Sets | Rice University |
| Language | English |
| Detected Language | English |
| Type | thesis, text |
| Format | application/pdf |
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