Efficient surface processing by ultrafast XUV/NIR dual action

We have developed a novel method for efficient structuring of the surface of materials by applying femtosecond near infrared laser pulses simultaneously with a weak extreme ultraviolet beam, which leads to a very strong radiation-matter interaction and brings a dramatic increase of the surface processing speed. We present our recent experimental results on surface nanostructuring of thin films of amorphous carbon and polymethyl methacrylate deposited on bulk substrates and discuss the underlying physical mechanisms. In the case of amorphous carbon, large areas of laser-induced periodic surface structures with a spatial period of 550 nm were created, having their origin in laser-induced convective currents. Our method provides a powerful tool for fast modification of tribological properties of the irradiated sample.