Investigation of laser induced plasma-assisted ablation of glass in presence of magnetic field

This paper summarizes the experimental investigation of glass drilling using laser-induced plasma-assisted ablation. In the experiments, a nanosecond pulsed laser with a wavelength of 532 nm as the laser source and copper with 2 mm thickness as the metal substrate are used, and two permanent neodymium magnets (4500-4800 G) are used to apply an external magnetic field to drill holes in the laboratory slide glass. The laser fluence was selected in 4 levels of 1, 1.5, 3 & 3.5 J/cm2 and the characteristics of the holes produced with 50 laser shots were examined in terms of dimensions and morphology. It was observed that by applying a magnetic field, the material removal rate increases about 2 to 2.4 times in the lower fluences and 31 to 35 times in the higher fluences. In the magnetic field absence for different laser fluence, the hole depth and diameter changed from 1.6 to 32 and 10 to 100 microns, and in its presence, they change from 3 to 76 and 11 to 380 microns, respectively. So the drilled hole depth and diameter increase up to 230% and 320% respectively, by applying a magnetic field. Metal deposition on glass in magnetic field absence is distributed symmetrically around the hole entrance, but in magnetic field presence, it occurs with high density and cohesion on one side of the hole.