AbstractPhotons can carry quantum information, but do not interact with each other. One way of enhancing interaction between photons is via their interaction with matter, two-level systems being the simplest example. And the best way to enhance matter interaction and control photon emission is to use wavelength scale cavity structures and Cavity Quantum Electrodynamics (CQED).
This thesis is about designing, simulating and fabricating such cavity structures. The goal is to design resonance cavities which will have a high enough Quality factor (Q-factor) and small enough modal volume to be able to observe spontaneous emission modification (Purcell effect) and strong coupling with quantum dots or NV-centres. The Purcell effect is useful for single-photon sources for quantum information processing (cryptography, computing, teleportation, etc), while strong coupling would allow the creation of all-optical switches and of quantum memories using spin-photon entanglement. A spin-photon entangler is a fundamental gate that would allow the preparation of multiple qbits (photons and spins) in complex entangled states (cluster states) that could allow scalable quantum computation.
After introducing the theoretical background of photonic crystals more in detail and their potential applications in chapter 1, I will present the tools and methods used for the electromagnetic simulations in the time and frequency domains and the analysis of the results in chapter 2. The main content of this thesis are simulation results for optical cavities in one-dimensional (1D) and three-dimensional (3D) photonic crystals, which will be presented in chapters 3 and 4 respectively. Some of the simulated structures were also fabricated using Focused Ion Beam (FIB) etching and Direct Laser Writing (DLW). These methods and the resulting structures will be discussed in chapter 5. Some preliminary optical characterization results of fabricated 3D photonic crystals using Fourier Image Spectroscopy (FIS) will be shown in chapter 6, as well as the use of higher index materials via DLW or backfilling. Finally, I will conclude in chapter 7, along with some considerations on further work to be undertaken in the future.
|Date of Award||24 Jan 2017|
|Supervisor||John G Rarity (Supervisor) & Ruth Oulton (Supervisor)|