Excimer laser radiation (XeCl, lambda=308 nm and ArF, lambda=193 nm) h
as been used both to cut chemical vapour-deposited diamond-coated tung
sten wires (diamond fibres) of diameter less than or equal to 200 mu m
and to smooth and profile the diamond surface. The effects of ablatio
n and localized heating in the focal volume on the diamond and the tun
gsten core are described, and compared with results obtained for a Nd:
YAG laser. The laser fluence and/or intensity, beam homogeneity and an
gle of incidence were identified as key parameters in ultraviolet lase
r-induced ablation of diamond-coated wires and fibres. Surface smoothi
ng may lead to increase fibre strength.