UV-induced index changes in undoped fluoride glass
Undoped fluoride glass slides have been exposed to pulsed 193-nm ultraviolet (UV) irradiation. Their absorption changes have been measured to evaluate UV-induced index changes using Kramers-Kronig relation. A layer-peeling polishing technique was applied to characterize the local UV-induced index change of highly absorbing glass. Index changes up to 1.75 x 10(-4) have been evaluated with this method in fluorozirco-aluminate glass. Fluoroaluminate and fluorozirconate glass showed only small index changes of about 2.0 x 10(-6) and 2.6 x 10(-6) at a wavelength of 1550 nm.