Surface structuring of rutile TiO2(100) and (001) single crystals with femtosecond pulsed laser irradiation

Laser-based surface patterning of rutile TiO2 monocrystals with (001) and (100) surface orientation is investigated following irradiation by a femtosecond KrF laser (248 nm) with variable fluences and multiple linearly polarized beams. Different types of structures were observed: volcano-like craters, nanoparticle-covered structures, ripples, and grooves. Furthermore, two kinds of distinct laser-induced periodic structures, 1D and 2D patterns, were observed. Morphological maps of characteristic surface morphologies were produced for each crystalline orientation, which indicate the significant influence of the crystalline anisotropy.