MULTI-WAVELENGTH LASER IRRADIATION OF Be-C-W COATINGS

BeCW (3:2:1) amorphous films were irradiated with three laser wavelengths of 300, 550 and 1350 nm having a comparable energy and respectively power density. Ablated volume and preferential ablation of lighter elements seemed independent of the photon's energy, but rather on their number. Carbon and Be clustering and crystal formation into the amorphous coating were more effective with more energetic photons. Graphite structures formation was recorded for fluencies below the ablation threshold. For longer laser wavelengths, carbon atoms tend to organize in ring structures and fullerene formation was recorded around the ablation zones. Be crystals formed in the ablation zone vicinity tend to be stretched toward the film surface and toward the ablation center suggesting more defects into the formed structures for these zones.