Surface nanostructuring of Ni/Cu foils by femtosecond laser pulses

This work examines the effect of high-power femtosecond laser pulses on Ni/Cu bilayer foils produced by electrodeposition. We consider nanostructures formed at different laser beam parameters and under different ambient conditions. The surface nanostructures obtained in air and water have mostly the form of quasi-periodic ripples with a characteristic period of 400-450 and 370-390 nm, respectively, at a laser wavelength of 744 nm, whereas the nanostructures produced in ethanol and benzine have the form of spikes, typically spaced 400-700 nm apart. Femtosecond laser nanostructuring of metals is for the first time proposed, and experimentally tested, as a viable approach to producing anti-reflective coatings on the surface of polymer replicas.