Femtosecond laser–matter interaction of tungsten carbide

We investigate the femtosecond laser–matter interaction for a tungsten carbide with 10% of cobalt. A femtosecond laser (1030 nm) with a pulse duration of 400 fs was used. For cumulated fluences between 1.4 and 4 J / c m 2 , laser-induced periodic surface structures (LIPSS) could be produced with a low ablation rate. LIPSS had a spatial period of 665 nm and an amplitude of 225 nm. The athermal ablation threshold fluence ranged from 0.35 to 11 J / c m 2 in cumulated fluence for a range between 1 and 100 pulses. Thus, dimples could be fabricated without any thermal effects. In addition, the incubation coefficient and optical penetration depth of tungsten carbide were determined. They were equal to 0.79 and 19 nm, respectively.