Clive Edward Hall

Electroanalytical applications of boron-doped diamond microelectrode arrays.

The electrochemical characteristics of a novel all diamond fabricated boron-doped diamond microelectrode array (BDD-MEA) are critically appraised. The voltammetric response of simple electron transfer processes has been investigated and found to generate sigmoidal voltammetric curves. Furthermore, the device has been utilized for various analytical applications including, the direct detection of 4-nitrophenol over the concentration range 1.8-9.2muM, manganese over the range 0.1-4.8muM and the indirect determination of sulfide producing a limit of detection of 23muM.

Use of CVD diamond in high-power CO2 lasers and laser diode arrays

Recent advances in CVD diamond growth and processing technology allow this material to be used effectively in a number of high-power laser applications. New data will be presented on the optical properties at 10.6 micrometer relevant to the use of CVD diamond as optical elements in high-power CO2, lasers. It will be shown that with the current form shape capability, it is possible to achieve sub- fringe flatness (at 633 nm wavelength) on components with diameter greater than 100 mm and that shallow lens with radii of curvature greater than 10 m can be routinely produced. New results will be presented on the influence of the polycrystalline structure on the absolute absorption coefficient at 10.6 micrometer and on the laser damage thresholds, showing that the power density required to cause continuous wave laser damage in CVD diamond of high quality can be higher than that of current optical materials. Theoretical modeling results will be presented on the use of CVD diamond for the heat management of laser diode arrays. Issues such as thermal-mismatch-induced stress and form shape requirements for uniform operation will be discussed.