https://phys.org/news/2018-11-laser-contamination-aircraft-surfaces.html > Summarising the process in a press release by the Fraunhofer Institute for Material and Beam Technology IWS, Dr Tim Kunze said: "With our process, we want to prevent any form of contamination on aircraft surfaces." He added, however, that "it would also be a success if we could at least reduce it considerably." > The same press release notes that the engineers have used a direct laser interference patterning (DLIP) technique. This involves the use of special optics to split a single laser beam into several partial beams that recombine on the metal surface to be structured. It creates precise and controllable light patterns. "If the interference pattern is focused onto a titanium sheet, the high-energy laser light melts and ablates the material in the bright areas, while it leaves the material unaffected in the dark areas."