Sabas, Jerico2011-05-242011-05-242010http://udspace.udel.edu/handle/19716/5914The limitations facing electronics integrated circuits have placed an imminent wall for the progression of computational speeds and bandwidth, opening the door for research of the optical properties of materials. Photonic crystals (PhCs) are projected as the fundamental platform for the development of photonic integration. These PhCs provide novel approaches to control the propagation of light using dielectric structures that can be scaled down to nanometer dimensions for near infrared (NIR) or visible light applications, or scaled up for microwave or millimeter-wave applications. The initial interest in PhCs arose from the discovery of a photonic bandgap that made them suitable for a variety of applications. The possibilities of PhCs were further expanded with the understanding of the unique dispersion properties of PhCs. This thesis is concerned with a particular dispersion property of PhCs that permits the propagation of a beam of light through the PhC without divergence despite the fact that no physical route is introduced; this dispersion property is fittingly identified as self-collimation. We engineered the dispersion properties of 2D periodic structures composed of dielectric rods to demonstrate, numerically and experimentally, the existence of self-collimation in PhCs in the microwave frequency regime. We designed and fabricated a low-index-contrast (LIC) PhC and experimentally demonstrated self-collimation, both in amplitude and phase, and measured the transmission efficiency for the LIC PhC slab. These results achieved for LIC PhCs provided principal insights into self-collimation that allowed us to extend our work to a high-index-contrast (HIC) PhC design to improve the confinement of light within the PhC. We designed, numerical simulated, and fabricated a PhC made with high-index ceramic rods and experimentally demonstrated a significant improvement in self-collimation compared to the LIC PhC. In particular, we addressed the issue of coupling the PhC to a coaxial medium by designing an input/output (I/O) coupler. We fabricated this coupler as a hybrid of commercially-available and original components and experimentally characterized the coupling efficiency with both the LIC and HIC PhCs.Photonic crystalsMicrowave opticsDispersionThesis