Polymicro's FDP range of fibre is designed for applications in the deep UV region (190nm to 325nm) where effects of high levels of UV radiation on the transmission of a silica core optical fibre must be considered. Solarisation changes depend on the type of fibre used as well as the intensity and spectral output of the UV source. These changes are wavelength dependent. The FDP fibres have a Numerical Aperture of 0.22 +/-0.02 and a Full Acceptance Cone of 25.4 degrees. A Polyimide buffer is standard.