METHOD OF, AND APPARATUS FOR, LASER BLACKENING OF A SURFACE, WHEREIN THE LASER HAS A SPECIFIC POWER DENSITY AND/OR A SPECIFIC PULSE DURATION

摘要

A method of blackening a surface, comprises applying laser radiation to the surface of a target (10) to produce a periodic arrangement of structures on the surface of the target (10), wherein the laser radiation comprises pulsed laser radiation comprising a series of laser pulses and the power density of the pulses is in a range 2 GW/ cm2 to 50 GW/cm2 or 0.1 TW/cm2 to 3 TW/cmz, and/or a pulse duration between 200 femtoseconds to 1000 picoseconds.