No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

This thesis is concerned with the theoretical study of one-dimensional and two-dimensional photonic structures. Plane-wave calculation methods have been employed to model one-dimensional waveguides and two-dimensional photonic crystals. The one-dimensional structures considered are slab waveguide interferometer devices. A transfer matrix method is described which has been implemented in a biosensor technique know as dual polarisation interferometry. The method presented is used for the characterisation of thin biological films. A similar slab waveguide device is described for the wavelength locking of diode lasers and a novel athermal solution to the problem is proposed. The study of two-dimensional photonic crystals employed a standard bandstructure method and also proposed new approaches to complex photonic bandstructures which are not believed to be available elsewhere. An interface matching calculation is described which employs complex photonic bandstructures and is believed to be the first use of the method described for photonic structures. The theoredcal methods are applied to consider the super- prism effect in square and hexagonal lattice photonic crystals. Optimum superprism structures are arrived at for both lattices. Reflection results from the optimum hexagonal structure are also considered, combined with coupling efficiency to the superprism mode. As a result of the work on photonic crystals new theoretical approaches have been described and implemented to assist with their establishment as calculation tools for two- dimensional photonic crystal structures.

No description available.

The sports ball market is extremely competitive and in the US alone valued in excess of $1305 million (SGMA 2008). Original equipment manufacturers (OEMs) are continually trying to create a competitive edge over their rivals. In order to research and develop sports balls it is vital to quantitatively measure launch and flight characteristics of the ball, in an attempt to create a ball that has better flight and/or impact characteristics. A launch or flight monitor allows consistent measurement and benchmarking of the ball under test. Current top of the range soccer ball monitors are assessed for performance. Predominantly the sports engineering community uses high speed video (HSV) cameras in this benchmarking process. This technique however is extremely susceptible to errors in spin measurement. These errors are explored in detail and recommendations are given in order to improve the measurements. The properties of laser light make it an ideal tool for accurate, non-contact measurements. It has gained such widespread use, that living in the 21" century it is inconceivable to avoid laser technology. In this thesis, optical laser techniques are pursued for ball launch angle, velocity and spin measurement. In order to successfully utilise these techniques a system that is capable of accurately steering the laser beam to the desired target is developed. A novel laser tracking system (NLTS) has been designed, developed and proven to work successfully, allowing tracking capability of an arbitrarily moving soccer ball, that has no special fiducials. The system is demonstrated to be capable of measuring the position of the ball in space, therefore the NLTS is capable of acting as a launch monitor. The system is proven to track soccer balls in the laboratory and in a more realistic player testing environment. A valuable design feature is that the natural and ambient lighting conditions are inconsequential for the operation of the system. The tracking technique could be applied to any sports ball and could conceivably be transferred to other applications, e.g. military and automotive. Single point vibrometry work and the NLTS are combined to add spin measurement capability. Actual and measured spin rate values show high levels of similarity when tracking a ball with angular, but no translational velocity. A purpose built 'pendulum rig' is used to carry out measurements on a ball with both translational and angular velocity. The testing highlights how influential the radial measurement distance from the spin axis is, regarding the outputted spin rate value. The current set-up would require further development to allow accurate spin rate measurement using the 'pendulum rig'. The main sources of error and recommendations for future developments of this device are outlined and discussed.