Photoinduced surface expansion of fluorozirconate glasses

Fluorozirconate glasses show surface changes when they are exposed to a bandgap light fringe pattern at 193 nm. The photoinduced phenomena include the generation of both a deformation (dilation) and a thin grating at the sample surface. This is the first time that an UV induced change in the shape of the surface is observed in fluoride glasses. A structural approach is proposed 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.