Coupling Plasmonic Metamaterials To Single-Quantum-Well Gain

Reducing unfavourable losses in metallic nanostructures by optical gain is currently one of the central topics in plasmonics and metamaterials research. The main prerequisite for this is the coupling between the plasmonic structures and the gain medium. This thesis investigates the coupling mechanism between split-ring resonators and single quantum wells. The focus lies on pump-probe experiments that give evidence for coupling and show this coupling to be dominated by the plasmonic near-fields

Coupling Plasmonic Metamaterials to Single-Quantum-Well Gain

Reducing unfavourable losses in metallic nanostructures by optical gain is currently one of the central topics in plasmonics and metamaterials research. The main prerequisite for this is the coupling between the plasmonic structures and the gain medium. This thesis investigates the coupling mechanism between split-ring resonators and single quantum wells. The focus lies on pump-probe experiments that give evidence for coupling and show this coupling to be dominated by the plasmonic near-fields

Probing optical chirality in the near field of plasmonic nanostructures

PublishedWe directly probe the optical chirality in the near field of plasmonic nanostructures coated with a dye-doped polymer film by measuring the photoluminescence enhancement and analysing it with respect to its circular polarisation state

Ultrathin Quadrifilar Spirals and Spiral Ensembles

We investigate the eigenmodes of both ultrathin quadrifilar spirals and ensembles made up of such spirals by comparing experimental near-field scans with numerical finite-element models. These modes can be understood in the picture of electric and magnetic localized spoof plasmons.EPSRC through the QUEST programme; “The Quest for Ultimate Electromagnetics using Spatial Transformations (QUEST).

Asymmetric dot dimers – optical properties and interactions

We present a study of the rich optical behaviour of the dark (grey) modes exhibited by asymmetric dot dimers and how this behaviour is modified upon interaction between dimers

Plasmonic meta-atoms and metasurfaces

Despite the extraordinary degree of interest in optical metamaterials in recent years, the hoped-for devices and applications have, in large part, yet to emerge. It is becoming clear that the first generation of metamaterial-based devices will most probably arise from their two-dimensional equivalents — metasurfaces. In this Review, we describe recent progress in the area of metasurfaces formed from plasmonic meta-atoms. In particular, we approach the subject from the perspective of the fundamental excitations supported by the meta-atoms and the interactions between them. We also identify some areas ripe for future research and indicate likely avenues for future device development.Engineering & Physical Sciences Research Council (EPSRC)Leverhulme Trus

Electromagnetic Properties of Ultrathin Quadrifilar Spirals and Their Complementary Structures

Published

A Study in Asymmetry: Resonances in Arrays of Asymmetric Disc Dimers (Invited)

Published

Probing the chiral nature of electromagnetic fields surrounding plasmonic nanostructures

Copyright © 2013 American Physical SocietyWe investigate the chiral properties of near fields around plasmonic nanostructures and their relation to the electromagnetic chirality C. By combining chiral metal nanoparticles with achiral dye molecules and measuring the circular polarization dependence of the enhanced photoluminescence, we find a correlation between the dissymmetry of the luminescence enhancement and the calculated values of C. These effects are strong (∼10−1), despite the weak circular dichroism of the particles (∼10−5). We further show that C represents the chiral selectivity of the near-field coupling between an emitter and a nanoantenna