Picosecond-Laser 4-Beam-Interference Ablation as a Flexible Tool for Thin Film Microstructuring

Interference of laser beams with the high pulse energy opens an opportunity of direct structuring over large areas. We report results of the laser beam interference ablation of thin metal films on glass using an infrared picosecond laser. The laser beam was split into four beams by a diffractive optical element, and 4F imaging system was used to produce interference pattern on the surface of the metal film. Regular structures with a period of 5 μm were produced in thin films of various metals. A variety of periodical patterns can be formed using the method by controlling the process parameters.