The past few decades of solar observations have seen an increase in both the spatial and temporal resolution of data. The recent launch of the Solar Dynamics Observatory is the next step in a digital era and provides so much data that the satellite has its own Feature Finding Te…
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Optical resonators – two mirrors facing each other, separated by a distance – are a very well studied technology. However, even such a well understood technology can sometimes present surprises. The first part of this thesis investigates the surprising properties of some canonic…
In this thesis, a hybrid photorefractive liquid crystal cell structure with the addition of a thin 40nm Gold layer is proposed that demonstrates significant photorefractive control of Surface Plasmon Polaritons (SPP). The photorefractive effects are generated through optically c…
Epoxy resin is widely used in high voltage apparatus as insulation due to its excellent mechanical, electrical and chemical properties. Fillers are often added to epoxy resin to enhance its mechanical, thermal and chemical properties. With the new development in nanotechnology, …
Breast cancer is the single most prevalent form of cancer in the UK today, accounting for around 16% of all diagnoses, and around 31% of diagnoses in women. The survival rates are good, however the prognosis is heavily dependent on the stage to which the cancer has progressed at…
Electrical insulation is known to age when under electrical stress. One cause of this is thought to relate to the movement and build up of charge within the insulation. The emission of a low level of light from polymeric materials when under electrical stressing is shown to occu…
Radio galaxies and quasars are among the largest and most powerful single objects known and are believed to have had a significant impact on the evolving Universe and its large scale structure. Their jets inject a significant amount of energy into the surrounding medium, hence t…
This thesis describes the optical and electrical properties of colloidal PbS nanocrystals synthesized in aqueous solution and comprising different capping ligands and/or matrices. Post-synthesis thermal annealing of thiol-capped PbS colloidal quantum dots (QDs) is discussed and …
This thesis outlines problems in the estimation of concentration value of an absorber present in a medium that is scattering and shortcomings of using the currently available techniques for the characterisation of such a scattering medium. The work describes experiment and analy…
Multimodal neuroimaging using a combination of Magnetoencephalography (MEG) and ultra-high-field fMRI are used in order to gain further insight into the neural oscillations and haemodynamic responses in the somatosensory cortex. Single pulse electrical median nerve stimulation (…
The work presented in this thesis is intended to contribute towards the understanding of the cerebral vascular behaviour in response to changes in neuronal activation. The blood oxygenation-level dependent (BOLD) functional magnetic resonance imaging (fMRI) signal provides an in…
Excited states in 155Lu and 158Ta have been populated in fusion evaporation reactions at the Accelerator Laboratory at the University of Jyvaskyla. Gamma-ray spectroscopy techniques have been employed, using both the Jurogam spectrometer at the target position and the GREAT spec…
We study the low temperature magnetic ordering of rare-earth pyrochlores. The dominant magnetic interaction: nearest neighbour antiferromagnetic Heisenberg exchange, is frustrated with a macroscopic ground-state degeneracy. This degeneracy is lifted by weaker interactions, stabi…
The sensitivity of the next generation of interferometric gravitational wave detectors will be limited in part by thermal noises of the optics. It has been proposed that using higher-order Laguerre-Gauss (LG) beams in the interferometers can reduce this noise. This thesis docume…
Metal hydride materials have attracted much interest for their potential use as hydrogen storage materials. Complex hydrides are amongst the most promising due to their high gravimetric storage capacities and favourable de/rehydrogenation conditions. Here, mixed anion complex hy…
The application of chemical ground improvement using the electrokinetic stabilisation(EKS)method has the potential to overcome problems soft highly compressibility soil. This technique has the potential to enhance the strength and reduce compressibility of a wide range of soils.…
This thesis is concerned with investigating the generation of ultra short, tunable pulses at high average power and / or high pulse energy using synchronously pumped optical parametric oscillators (OPO) and appropriate power-scalable fibre-amplifier pump sources. Two types of pu…
In the last decade well known materials such as metals and silicon have emerged as new materials for photonic applications leading to the growth of two important fields: plasmonics and silicon photonics. This thesis is divided in two parts with part I focusing on plasmonics, and…
Fiber lasers and amplifiers have undergone rapid development in the past two decades, evidenced by the almost exponential rise in their output powers. This project investigates various concepts relating to high-power operation of fiber sources, focussing particularly on mode-are…