Glass micromachining using the VUV F 2 laser

Abstract
Theoretical and experimental studies of the surface quality in 157 nm F2 laser-ablated glasses are reported. Limitations set by statistical fluctuations in the multi- mode beam and by stationary beam non-uniformity are explored together with materials issues such as laser-induced surface cracking. Experimental work on ablating polymethyl methacrylate, used as a low threshold medium for recording of the VUV beam, and soda lime glass are described. Use is made of the probe beam deflection technique to determine ablation thresholds, and a variety of methods adopted for characterizing and assessing the quality of ablated surfaces e.g. scanning-electron microscopy, mechanical and optical interference profiling and atomic force microscopy. Preliminary roughness measurements are compared with theoretical expectations and the implication for glass micromachining with the F2 laser discussed.