Photoinduced surface expansion of fluorozirconate glasses

Fluorozirconate glasses show surface changes when they are exposed to a ban dgap light fringe pattern at 193 nm. The photoinduced phenomena include the generation of both a deformation (dilation) and a thin grating at the samp le surface. This is the first time that an UV induced change in the shape o f the surface is observed in fluoride glasses. A structural approach is pro posed to explain the photoinduced glass dilation. The height of the surface dilation is enough to explain most part of the grating efficiency provided that a reasonable hypothesis is assumed. (C) 2000 Elsevier Science B.V. Al l rights reserved.