Deposition of transparent Al$_2$O$_3$ coatings with extreme wetting properties by nanosecond laser ablation of aluminum in background oxygen

Transparent aluminum oxide nanostructures with extreme wetting properties were synthesized by nanosecond laser deposition in background oxygen. The transparency and morphology of the samples were analyzed. Non-monotonic behavior of the transmittance coefficient was observed with varying background oxygen pressure in the range of 20 to 140 Pa, attributed to differences in the kinetics of ablation product dispersion. The evolution of the contact angle was studied, ranging from $\sim$5 to $\sim$120$^\circ$, during the storage of coatings in air under normal conditions.