Sensor applications of plasmonic and photonic structures

Abstract

The primary objective of this doctoral thesis is to investigate sensor applications that utilize plasmonic and photonic structures. This research explores three distinct optical phenomena for refractive index sensing within the visible and near-infrared spectral ranges, along with the proposal and fabrication of various sensor structures. The first section of this work focuses on relative humidity sensing based on guided-mode resonance. It comprises both theoretical and experimental investigations of a metal-cladding waveguide structure that includes a photoresist guiding layer and an analyte represented as a semi-infinite dielectric cladding. The second section discusses the use of surface plasmon resonance for sensing aqueous analytes in both spectral and angular domains. To achieve optimal sensor performance, a comprehensive analysis of reflectance spectra is conducted using an algorithm for proposed SPR structures that incorporate a protective layer, a bi-metallic plasmonic layer, and two-dimensional materials. Finally, the thesis explores the potential of cavity mode resonance for sensing gaseous analytes. This includes both theoretical and experimental investigations of a spacer-based cavity that utilizes distributed Bragg reflectors for relative humidity sensing.