UV laser radiation-induced modifications and microstructuring of glass

Modifications and microstructures are generated on the surface and in the volume of silicate glasses using pulsed UV laser radiation of small pulse length. During the interaction of pulsed excimer laser radiation (193 nm/20 ns, 248 nm/20 ns, 308 nm/40 ns, 351 nm/20 ns) and frequency-trippled Nd:YAG laser radiation (355 nm/10 ns) with intensities below the removal-threshold of the cerium- and silver-doped multi-component silicate glass absorption centers in the UV are induced. Subsequent thermal treatment and wet chemical etching results in crystallisation of the laser-illuminated absorbing region and in the fabrication of microstructures on the surface. Processing of sodalime- and boro-silicate glass with pulsed ArF excimer laser radiation (193 nm/20 ns) and frequency-doubled Nd:YAG laser radiation (532 nm, 1064 nm/40 ps) with intensities above the removal-threshold leads to microstructures including the generation of microcracks on the surface and in the bulk. The dynamics and the transmission of the expanding plasma and changes in the refractive index of the glass are investigated with Speckle photography using the pump and probe method. The determination of plasma emission and crack generation is carried out using high speed- and Nomarski photography. Morphological and chemical properties of the debris generated under defined processing gas atmospheres are investigated with REM, white light interferometry, XPS and EPMA. Induced absorption and changes of the crystalline-phase are probed using optical-spectroscopy and XRD as well REM. On the basis of these investigations the processes of the generation of induced absorption centers and crystallisation on the one hand and the generation of cracks and debris on the other hand as well as the quality of the produced microstructures is discussed