Physical Sciences and Mathematics Commons^™

Manipulation Tools For Laser-Cooled Rubidium Atoms : Ultrathin Optical Fibres And Magnetic Diffraction Gratings / Michael J. Morrissey., Michael J. Morrissey

Theses

This thesis describes the construction and characterisation of a standard six-beam configuration magneto-optical trap (MOT) used to cool and trap neutral ⁸⁵Rb atoms. This system is capable of producing a cloud of ~10⁸ atoms whose average temperature is in the sub-Doppler range. The fabrication process for the production of subwavelength tapered optical nanofibres (TONFs) is also described, as well as their guiding properties. These have many proposed applications in the field of cold atoms. However, significant technical progress must be made before many of these applications can be realised. The objective of the research work was to combine …

Characterisation Of Immunosensor Surfaces Using Scanning Force Microscopy, Eva Maria Gil Romero

Theses

The overall aim of this thesis was twofold. Firstly, to evaluate how scanning force microscopy (SFM) could be used to characterise the surfaces of immunosensors. Four aspects of immunosensor characteristics where SFM has particular application potential have been identified: (a) immobilisation chemistry and (b) the surface density, (c) orientation and (d) specificity of the immobilised antibodies. Secondly, to examine experimentally how the Explorer SFM instrument could be used for such characterisation.

The Explorer SFM instrument is of an open-loop actuator design that is exposed to the intrinsic inadequacies of piezoelectric actuators. In this regard, careful calibration has shown that achieving …

Fluoride And Phosphate Glass Whispering Gallery Micro-Resonators, Jonathan Ward

Theses

This PhD work focuses on spherical microlasers made from commercial and experimental laser glasses. The laser light in a microsphere is confined in a region called a whispering gallery mode, which has unique properties that allow for many nonlinear effects to be observed with only sub-mW pump powers. Efficient coupling of light into the microsphere is attained by using adiabatically tapered fibres fabricated using various heating methods including a CO₂ laser, a sapphire tube furnace and electric heaters. However, the best result is obtained using a fibre pulling rig with an oxy-butane torch as the heat source. This system …