Engineering Micro- and Nanoscale Cavities for Applications in Light Manipulation.

Abstract

With highly controllable optical field confinement, subwavelength-scale structures are capable of manipulating light behavior at UV, visible, and IR wavelengths. This light manipulation further enables ones to improve performance of optical devices such as lasers, photovoltaics, and detectors. In this dissertation, two applications of such subwavelength-scale cavities for improved optical performance will be introduced. First, the lasing threshold and optical property of photonic crystal microdisk lasers is improved in the presence of dielectric nanostructures, and the design concept of the nanostructure further paves the way toward higher efficiency microcavity lasers as light sources for photonic integrated circuits. Secondly, several designed plasmonic nanocavities will be presented in this thesis for spectrum filtering. These plasmonic nanostructures enable ones to achieve multifunctional structural color filters with high efficiency (>60%), good color purity (linewidth<70nm), and robust angular response (+-80 degree). The proposed plasmonic nanostructures have great potential for structural color filtering in LCD TV displays to further allow highly efficient displays with sharper colors and ultra-small pixel sizes. The proposed plasmonic nanocavities also open up the opportunity for a wide variety of applications such as photovoltaics, nanocavity emitters, miniature hyperspectral imaging, and high sensitivity index sensors.