Periodical Gratings in Mixed-Oxide Films by Laser-Interference Irradiation

Laser-interference structuring of sol–gel films without organic photopolymerization provides a single-step method for the production of periodic surface structures (see Figure) in titania–silica mixed-oxide films. The dependency of the structure depth and homogeneity, measured by white-light interferometry, on process parameters such as laser fluence and number of laser pulses has been evaluated. A mechanism for structure formation is proposed.