Surface structuring of glass with submicrometer features using selective laser etching

Selective laser etching (SLE) is a procedure to create customized micro-fluidic or micro-mechanical structures in glass. We aim to utilize SLE for optics production as well and report on detailed investigations of the glass structuring process by variation of stage speed, laser power, polarization and repetition rate of the laser to reduce the surface roughness to optical quality without any additional process steps. We show that a surface roughness of ≈30 nm can be achieved which is sufficient to fabricate optical components or integrated optical structures even for the visible wavelength range. Our results enable the fabrication of free standing micro-structures with a feature size of less than 1 µm in fused silica using SLE and KOH as etchant which enables the fabrication of optical gratings.