ELECTROMAGNETIC WAVE MANIPULATION USING METASTRUCTURES

Abstract

The field of electromagnetics has seen significant growth in research on optically resonant materials during the twenty-first century. While the idea of novel light-matter interaction kept reverberating throughout human history, it was during the latter half of the last century that formal conceptualization of the topic was seen, especially in the form of negative refractive index/ plasmonic materials. Over the last couple of decades, this area of research has seen exponential growth resulting into an exciting field of study known as metamaterials. Today, optical metamaterials represent a broad class of resonant materials with unnatural characteristics. This dissertation explores research in optically resonant materials from different angles. It attempts to connect the dots across different domains in the realm of metamaterials. Mathematical modeling has been used to understand the propagation characteristics of plasmonic waves. The results from analytical models have been compared with numerical studies. Computational simulations have also been conducted to design photonic metamaterial structures; the structures mainly consist of plasmonic and dielectric materials. The feasibility of such nanoscale structures for biomedical sensing applications has been explored by investigating how changes in refractive indices create changes in spectral responses of the resonators. Experimental work has been carried out using chemically active optical materials. Optodes have been developed using certain nanomaterials that can selectively trace potassium ions in a solution by displaying changes in absorption levels at specific frequencies. On-chip optical manipulation has been performed to observe the differences between simulation and experimental results. The objective has been to achieve suitable results for different industrial applications like biosensing and communications.