Selective laser etching (SLE) is a femtosecond laser-based technology that enables 3D printing of complex glass microparts in two technological steps: direct laser writing inside the volume of glass and subsequent etching. The SLE technology permits straightforward conversion of the desired CAD design to a 3D micropart. Even mm-size structures with a few micrometers of precision can be printed in this way. One example is threads for screws in glass. Sub-mm size thread structure is hard to fabricate in glass due to its spiral shape and the need for high precision and low surface roughness. These requirements must be met for the screw to be inserted inside the structure without damaging the thread.
