Control of Orientation and Periodicity of Laser-Induced Surface Structures on Metals

Laser-induced periodic surface structures (LIPSS) can be created on various materials, and they hold an exceptional potential for surface nanopatterning, enabling new industrial applications in medicine, biology, optics and other fields. However, LIPSS formation is typically restricted to a specific orientation and periodicity. In this work, a novel approach is demonstrated for full control of the LIPSS periodicity and orientation on metallic surfaces using a 1064 nm nanosecond laser. Analytical expressions and experimental verification are presented to show that by simultaneously manipulating three parameters of the laser beam, such as the polarization, angle of incidence, and direction of the laser scan along the surface, LIPSS can be formed with the desired geometrical configuration. This enhanced control opens vast possibilities for laser processing technologies as a flexible and highly competitive solution for advanced applications relying on surface modifications in the fields of anisotropic surface wettability, thermal and electrical conductivity, structured colors, diffraction gratings, and many others. This work presents a method for controlling the orientation and period of uniform laser-induced periodic surface structures on metal surfaces using nanosecond laser. Analytical and experimental results show that the LIPSS density and orientation can be adjusted over a wide spatial and angular range by simultaneously controlling laser polarization, angle of incidence, and beam scanning direction. image