Formation of micro/nano-metric holes/voids in Al2O3-coated boro-aluminosilicate glass by single pulse femtosecond laser irradiation

In this paper, we report the formation of periodic array of micro/nano-scale holes/voids on the surface of and inside Al₂O₃-coated boro-aluminosilicate glass by means of single pulse femtosecond laser irradiation. The lowest diameter of the nano-holes printed on the Al₂O₃ coating reaches down to 700 nm, whereas the lowest diameter of the voids inside the glass was 1.1 μm. The fabricated micro/nano-metric holes and voids show uniformity in size and shape throughout the sample area. We also investigate the surface property of the nanovoids´ evolved glass surface. We don´t observe any structure on the sample surface, when the voids have been evolved inside the glass sample. In addition, we investigate the formation mechanism of the micro/nano-holes or voids in our double-layer samples. We strongly believe that, the periodic micro/nano-voids array will be useful in fabricating various photonic/optical devices, especially, in spreading light.