Abstract

Materials processing with femtosecond lasers in often accompanied by an effect creating regular patterns on the surface first discovered by Birnbaum in 1965 [1]. The effect has been intensively studied in the meantime to understand the fundamental mechanisms and to be able to control their shape. The nanoscale surface structures appear on most type of materials in particular metals, semiconductors and even crystalline dielectric materials. Due to their regular nature the patterns are called laser induced periodic surface structures - LIPSS. As the creation mechanism does not rely on conventional material ablation, their shape and height are not a direct mapping of the laser intensity profile but are moreover principally determined by the laser wavelength, polarization, fluence and the number of consecutive pulses. As the orientation of the nano textures is known to be influenced by the polarization of the laser pulse [2] we engage radial and azimuthal polarization converters to manipulate the direction of the periodic structures as depicted in Figure 1. With different combinations of these influential parameters various different morphologies can be created to serve different applications with specific functions and surface properties, which are briefly introduced below.

© 2015 IEEE