Direct femtosecond laser surface structuring with complex light beams generated by q-plates

Direct femtosecond (fs) laser surface structuring became a versatile way to generate surface structures on solid targets demonstrating a high degree of flexibility and controllability in creating different types of structures for many applications. This approach demonstrated an alteration in various properties of the surface, such as optical properties, wetting response, etc. This paper focuses on direct fs laser surface structuring using complex light beams with spatially variant distribution of the polarization and fluence, with emphasis on the results obtained by the authors by exploiting q-plate beam converters. Although striking scientific findings were achieved so far, direct fs laser processing with complex light fields is still a novel research field, and new exciting findings are likely to appear on its horizon.