Hi Eric,

I have used a material called Hoya UV-34 (cut-off = 340nm) for this application
in the past. I think it is a discontinued material but a company called glass
perfection in the UK still sell it. I think you should be able to get a 5"
square piece for around 400-500GBP. The companys website should also give a
plot of the transmission at UV wavelengths. It has work well for me (for SU-8
applications).

Please feel free to ask any further questions

Novak
_____________________________________

Novak Farrington
Institute of Microwaves and Photonics
School of Electronic and Electrical Engineering
University of Leeds
Leeds LS2 9JT
UK

Mob. 07740 965069
Tel. +44 (0)113 343 2092
Fax. +44 (0)113 343 2032
email: eennf@leeds.ac.uk