Formation of nanostructures by femtosecond laser processing

The formation of laser-induced periodic surface structures (LIPSS) on metallic surfaces by femtosecond laser radiation was investigated. Various types of LIPSS could be formed on metallic surfaces such as copper and stainless steel. Nano-ripple formation was investigated as function of laser scanning speed, laser pulse number, and laser fluence. Hierarchical structures were generated on stainless steel surfaces and hydrophobic properties with water contact angles of about 145° could be achieved. It could be shown that direct femtosecond laser surface processing is a perfect tool for designing surface properties on micro- and nanometer scale which can be used for optical, biomedical, and tribological applications.