Ablation characteristics of cubic-boron nitride ceramic with femtosecond and picosecond laser pulses

Ablation of cubic-boron nitride (c-BN) ceramic irradiated by Ti:sapphire la ser (110 fs, 790 nm) and Nd:YAG laser (100 ps, 1.064 mum) pulses is compara tively studied. In the case of Ti:sapphire laser ablation, it is observed t hat the ablation depth per pulse has two different ablation regimes, being similar to the fs laser ablation of metals. The ablation threshold fluence for the 110 fs Ti:sapphire laser is estimated to be 15 mJ/cm(2) for low flu ence ablation, and 180 mJ/cm(2) for high fluence ablation. With x-ray photo electron spectroscopy signal and scanning electron microscope observation i t is evident that the surface ablated with the 110 fs Ti:sapphire laser pul ses remains as the BN layer itself and is not melted. With the 100 ps Nd:YA G laser ablation, the boron semiconductor layer is formed on the ablated su rface. (C) 2001 American Institute of Physics.