It is the aim of this proposal to look at new kinds of communication components that are made from ceramic dielectric material. The key innovation in these components is that they are based upon innovative ceramic shapes such as a helix or spiral. Such components could offer several substantial advantages in a modern communiation system. These improvements in the efficiency of communication systems would have very significant benefits for the general public and also for the mobile phone companies. If substantial increases in signal strength (of perhaps 3-5 dB) could be attained, through improved components, this would mean that emitted mobile phone radiation levels could be substantially reduced. Alternatively if the emitted power levels were kept the same then the number of new antenna masts required for new systems such as 3G could be dramatically reduced.

Electroceramics are exploited because they respond in useful ways to external stimuli, e.g. electric fields (varistors, relaxors), temperature (thermistors), or atmosphere (gas sensors). In some cases the best performance is achieved if the bulk ceramic is homogeneous (e.g. microwave dielectric or piezoelectric ceramics) whilst in other cases the behaviour depends upon carefully engineered grain boundary structures (for example PTC thermistors and varistors), or functionally graded materials. It is therefore important to understand, and optimise, the fine scale homogeneity of these materials. As the size of electroceramic components continues to reduce, ever smaller scale variations in a material's microstructure become significant, both from a device homogeneity and processing batch variability perspectives. These inhomogeneities can broaden or degrade the response of the bulk device, as may be seen in practice through a reduction in the quality factor of a microwave dielectric material, a change in the ease of domain switching in ferroelectrics, or a change in the temperature interval of the PTC transition in a thermistor. In cases where operation requires a high level of transient power dissipation, such as for varistor or thermistor protection devices, inhomogeneity can lead to localised mechanical stresses and (possibly) failure of the device. There is therefore a materials processing need to characterise, understand, and limit the extent of these microperformance variations.In this research project, we wish to develop SEM-based localised electrical property and electrical structure measurement techniques, specifically for electroceramic film applications, which we will use in parallel with other SEM based techniques (e.g.EBSD analysis)to study directly the link between microstructure, crystallography and local electrical performance in a wide range of semiconducting, dielectric and multifunctional electroceramic films. This 12 month programme of work is designed as a 'proof of principle' exercise and will address the following:1. Modification of our SEM-based conductive mode microscopy (CM) and local property measurement facility to allow quantitative study of local electrical structures and performance in thick/thin films.2. Development of measurement techniques to enable quantitative AC methodologies to provide localised capacitative/permittivity data from dielectric and related functional electroceramic films.3. Establishment and evaluation of a new local property characterisation technique based on measurements of the discharge profile of beam-injected charge into a thin film.Our approach will be to combine new experimental techniques with modelling/simulation studies. We will do this by developing our current SEM conductive mode facility to undertake studies of thin films and to evaluate the new measurement technique. We will quantify and interpret signals through parallel modelling and simulation studies, including Finite Element (FE).

Hollow core optical fibres guide light in a hollow (usually, gas-filled) core rather than in a solid glass core as in all conventional fibres. The use of a hollow core means that many of the constraints on optical fibre performance which are due to the properties of the core material are lifted (often by many orders of magnitude) and the fibres can by far outperform their more familiar conventional counterparts. There is a problem, however: how can you trap light in a hollow core? Substantial effort has been put into developing so-called photonic bandgap fibres over the last 20 years. These fibres rely on a complex cladding structure to trap light in the hollow core with low losses. They have been developed to a high degree but have been held back by some apparently insurmountable practical problems. These have especially constrained their performance at the short wavelengths which are important in many applications such as high precision laser machining and materials modification. The state-of-the-art laser systems can now deliver the necessary radiation for these applications: however, a truly flexible delivery system does not currently exist. This ability to deliver the pulsed laser light flexibly from the laser system to the point of application is a key advance required to develop practical and commercially viable applications. Over the last eighteen months, researchers in this collaboration and at a couple of other laboratories across Europe have demonstrated that a much simpler fibre design can actually be far more effective than the bandgap fibres. This is especially true at long wavelengths (in the mid-infrared) and at short wavelengths (eg 1 micron wavelength and below.) Numerical simulations now suggest that these designs can be extended to offer the possibility of their outperforming any existing optical fibres at almost any optical wavelength. This proposal is to demonstrate these fibres at a range of short wavelengths and to work with four UK-based companies to establish them as useful in manufacturing and clinical environments. This involves making fibres with several designs, verifying their performance, identifying the barriers to their use and overcoming them, and then working in the laboratories of our collaborators to establish them as useful on the factory floor and also in medical and engineering measurements. Along the way, we aim to demonstrate the lowest-loss optical fibre ever (at a longer wavelength) and to investigate whether these designs can be extended to deliver laser beams with low beam quality.