Micro-drilling transparent dielectric materials by using non-diffracting beams impinging orthogonally to the sample can be performed without scanning the beam position along the sample thickness. In this work, the laser micromachining process, based on the combination of picosecond pulsed Bessel beams with the trepanning technique, is applied to different transparent materials. We show the possibility to create through-apertures with diameter on the order of tens of micrometers, on dielectric samples with different thermal and mechanical characteristics as well as different thicknesses ranging from two hundred to five hundred micrometers. Advantages and drawbacks of the application of this technique to different materials such as glass, polymer, or diamond are highlighted by analyzing the features, the morphology, and the aspect-ratio of the through-holes generated. Alternative Bessel beam drilling configurations, and the possibility of optimization of the quality of the aperture at the output sample/air interface is also discussed in the case of glass.
We present a study on the micro-drilling process by means of a picosecond Bessel-Gauss beam, and the achievements obtained on a 200-µm-thick AF32 glass sample in different laser fabrication regimes. In particular, we compare the results and morphology of the holes generated with a high-repetition-rate pulsed laser, respectively, in the single-pulse mode and in the burst mode machining regimes. We highlight the advantages or drawbacks of these two types of microfabrication for the generation of through-holes. For a given pulse density, the burst mode turns out to be advantageous with respect to the single-pulse mode fabrication in terms of lower energy per pulse needed and higher speed of drilling, even if the stronger thermal effects can more easily lead to surface cracks. On the other hand, by adjusting the pulse density below a critical level, it can be shown that the single-pulse regime can be adopted for the generation of more regular through-holes and cleaner apertures, even if multiple pass operation is likely to be needed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.