Permanent grating patterns have been written directly in lead-tin-fluo
rophosphate glasses by use of UV radiation. The effect of photorefract
ion is studied in different tin-fluorophosphate compositions. Recorded
gratings are found to be volume rather than surface elements. The ind
uced index changes are comparable with those seen in GeO2-SiO2 glasses
. (C) 1998 Optical Society of America.