Periodic Striations On Beryllium And Tungsten Surfaces By Indirect Femtosecond Laser Irradiation

Femtosecond laser pulses with lambda = 800 nm were focused in air at one atmosphere and in deuterium (D) at low pressure. Submicron periodic structures were observed on surfaces made of Be, W and a mixture of Be-W immersed in these gases and placed nearly parallel with the laser beam, at 300 mu m from the focal spot. In air, no structures were observed on Be. For the Be-W mixture, the periodic structures were uniform and parallel when formed in D but irregular in air. In this last case the striations were organized into small patches of 1 to 2 mu m in size. (C) 2014 AIP Publishing LLC.