3D microstructuring inside Foturan glass by femtosecond laser

We show that femtosecond (fs) laser enables us to produce true three-dimensional (3D) microstructures inside a photosensitive glass (Foturan), which has superior properties on transparency, hardness, and chemical and thermal resistances. Exposure to the focused laser beam writes latent images inside the glass. Modified regions are developed by a post baking process and then preferentially etched away in dilute hydrofluoric (HF) acid. In general, an embedded microchannel fabricated by focal beam scanning perpendicularly to the laser beam becomes an elliptical shape with a cross section of large aspect ratio. We demonstrate that the aspect ratio can be improved by using two advanced irradiation methods.