Influence of scanning velocity on femtosecond laser direct writing lines on FOTU

Lines are induced on the surface of a photosensitive (FOTURAN) glass by focused femtosecond laser transverse writing with scanning velocity in a wide range of 40-1800 μm/s. The formed lines are analyzed using scanning electron microscope (SEM) and optical microscope (OM). It is observed that three distinct morphologies of lines are produced depending on the scanning velocity. Lines written in low velocity level (40-100 μm/s) and high velocity level (1000-1800 μm/s) are uniform and regular, while