Study on laser ablation of glass using MHz-to-GHz burst pulses

Abstract

The authors report on the use of a burst-mode ultrashort pulsed laser source with an emitting wavelength of 1030 nm on to micro-machining plane areas of glass with different pulse durations, burst energies, and number of sub-pulses per burst with intra-burst rates of 65 MHz and 2.5 GHz. In the investigated parameter range, the maximum specific removal rates are obtained with \(11.2\,\upmu \text{m}^{3}/\upmu \text{J}\) for MHz bursts and \(27.0\,\upmu \text{m}^{3}/\upmu \text{J}\) for GHz bursts, being up to four times higher compared to the non-burst regime. The depth per scan and the surface roughness increase at higher burst energies and at a higher number of sub-pulses per burst, respectively. Furthermore, a significant difference in the resulting surface topography between MHz and GHz bursts is shown by SEM images, mainly depending on the number of sub-pulses per burst.