Return to search

Computer Generated Geometric Phase Holograms

<p> This dissertation concerns the fabrication, analysis, and simulation of computer generated geometric phase holograms (CGHs). The current knowledge of CGHs is advanced to enable the creation of new sophisticated optical elements with unique characteristics. These elements enable new technologies related to displays, astronomy, sensing, beam-steering, beam-shaping, and more.</p><p> First, a novel direct-write system for CGH creation is presented. A mathematical description of the system is developed which allows the result of a given scan pattern to be predicted. The accuracy of the model is validated with various scan patterns, then a high-quality direct-write polarization grating and q-plate are fabricated for the first time.</p><p> With a system capable of creating CGHs, the most common and useful CGHs are explored in depth: the polarization grating, the geometric phase lens, and the Fourier geometric phase hologram. For each element, the possible scan patterns and parameters and their effect on the resulting element's quality are studied. Ultimately, the optimal scan patterns and parameters are found, then best-quality elements of each type are created and characterized. </p><p> Finally, a new tool for simulating periodic CGHs is developed. This begins with the derivation of the algorithm, which is based on the finite-difference time-domain (FDTD) method. Next tool's capabilities are verified by simulating many test structures and comparing the results to known solutions. The tool is used to simulate, for the first time, a CGH multiple beam splitter and a GPL array.</p>

Identiferoai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:3710731
Date14 August 2015
CreatorsMiskiewicz, Matthew Nile
PublisherNorth Carolina State University
Source SetsProQuest.com
LanguageEnglish
Detected LanguageEnglish
Typethesis

Page generated in 0.0646 seconds