Investigation of Laser-Induced Surface Structures (LIPSS) on quartz and evaluation of their influence on material wettability

Abstract

We report here on a study of the generation of Laser-Induced Periodic Surface Structures (LIPSS) on quartz upon irradiation with linearly polarized femto-second laser pulses (pulse duration τ = 200 fs and central wavelength λ = 1030 nm). Two different regimes of LIPSS were observed, Low-Spatial-Frequency-LIPSS (LSFL) and High-Spatial-Frequency-LIPSS (HSFL), characterized by different spatial periods and orientations. The formation of these two types of structures was investigated by varying the laser fluence, the number of laser pulses and the laser repetition rate. Once established how these parameters affect the generation of LIPSS, extended HSFL patterns (25 × 25 mm2) were realized, and their wettability was compared to that of pristine quartz. Contact angle measurements showed that HSFL textured quartz exhibits a super-hydrophilic behaviour, with a measured contact angle equal to 7.6°, with respect to pristine quartz which results simply hydrophilic and shows a contact angle equal to 41.2°.