Wave propagation in photonic crystals and metamaterials: Surface waves, nonlinearity and chirality
Description/Abstract
Photonic crystals and metamaterials, both composed of artificial structures, are two interesting areas in electromagnetism and optics. New phenomena in photonic crystals and metamaterials are being discovered, including some not found in natural materials. This thesis presents my research work in the two areas. Photonic crystals are periodically arranged artificial structures, mostly made from dielectric materials, with period on the same order of the wavelength of the working electromagnetic wave. The wave propagation in photonic crystals is determined by the Bragg scattering of the periodic structure. Photonic band-gaps can be present for a properly designed photonic crystal. Electromagnetic waves with frequency within the range of the band-gap are suppressed from propagating in the photonic crystal. With surface defects, a photonic crystal could support surface modes that are localized on the surface of the crystal, with mode frequencies within the band-gap. With line defects, a photonic crystal could allow the propagation of electromagnetic waves along the channels. The study of surface modes and waveguiding properties of a 2D photonic crystal will be presented in Chapter 1. Metamaterials are generally composed of artificial structures with sizes one order smaller than the wavelength and can be approximated as effective media. Effective macroscopic parameters such as electric permittivity {epsilon}, magnetic permeability {mu} are used to characterize the wave propagation in metamaterials. The fundamental structures of the metamaterials affect strongly their macroscopic properties. By designing the fundamental structures of the metamaterials, the effective parameters can be tuned and different electromagnetic properties can be achieved. One important aspect of metamaterial research is to get artificial magnetism. Metallic split-ring resonators (SRRs) and variants are widely used to build magnetic metamaterials with effective {mu} < 1 or even {mu} < 0. Varactor based nonlinear SRRs are built and modeled to study the nonlinearity in magnetic metamaterials and the results will be presented in Chapter 3. Negative refractive index n is one of the major target in the research of metamaterials. Negative n can be obtained with a metamaterial with both {epsilon} and {mu} negative. As an alternative, negative index for one of the circularly polarized waves could be achieved with metamaterials having a strong chirality ?. In this case neither {epsilon} nor {mu} negative is required. My work on chiral metamaterials will be presented in Chapter 4.
| Creator/Author: | Wang, Bingnan |
|---|---|
| Publication Date: | 2009 Dec 03 |
| OSTI Identifier: | OSTI ID: 972072 |
| Report Number(s): | IS-T 2645 |
| DOE Contract Number: | DE-AC02-07CH11358 |
| Other Number(s): | TRN: US201005%%174 |
| Resource Type: | Thesis/Dissertation |
| Research Org: | Ames Laboratory (AMES), Ames, IA (United States) |
| Sponsoring Org: | USDOE Office of Science (SC) |
| Subject: | 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CHIRALITY; DEFECTS; DIELECTRIC MATERIALS; ELECTROMAGNETIC RADIATION; ELECTROMAGNETISM; LINE DEFECTS; MAGNETIC SUSCEPTIBILITY; MAGNETISM; OPTICS; PERMITTIVITY; REFRACTIVE INDEX; RESONATORS; SCATTERING; TARGETS; VARIABLE CAPACITANCE DIODES; WAVE PROPAGATION; WAVELENGTHS |
| Country of Publication: | United States |
| Language: | English |
| Format: | Size: 15,845 Kb |
| Update Date: | 2010 Mar 29 |
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