Date of Degree

10-2014

Document Type

Dissertation

Degree Name

Ph.D.

Program

Physics

Advisor

Vinod M. Menon

Subject Categories

Nanoscience and Nanotechnology | Optics | Physics

Keywords

Light-Matter, Metamaterials, Nano-composite, Photoluminescence, Quantum Dots, Tunable

Abstract

This thesis describes the design, fabrication and characterization of certain nanostructures to engineer light-matter interaction. These materials have peculiar dispersion properties owing to their structural design, which is exploited to control spontaneous emission properties of emitters such as quantum dots and dye molecules. We will discuss two classes of materials based on the size of their unit cell compared to the wavelength of the electromagnetic radiation they interact with. The first class are hyperbolic metamaterials (HMM) composed of alternate layers of a metal and a dielectric of thicknesses much smaller than the wave- length. Using a HMM composed of silver and titanium dioxide, we demonstrate the optical equivalent of the well-known Lifshitz transition in electronic systems. Then we describe the development of a tunable HMM whose optical properties can be tuned. The tunability is achieved by exploiting the insulator to metal phase transition in vanadium dioxide. We then discuss the second class of materials - photonic crystals, in which the size scale of the unit cell is of the order of the wavelength of electromagnetic radiation they interact with. Due to strong scattering in such systems, bandgaps open up in certain directions, which we use to modify the spontaneous emission of a fluorescent dye.

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