Possibility of ultra-precise laser induced ablative etching of diamond materials was investigated. Different types of lasers were used. Natural sigle crystal diamond, poly and nanocrystalline CVD diamond, amorphous diamond-like films were irradiated in air and vacuum at laser fluencies 0.01÷20 J/cm2. It is found that depending on material, laser fluence and wavelength physical and chemical regimes of materials ablation can be realized. The role of surface graphitization and oxidation, charge carriers generation in diamond is studied. It is shown that ablation rates as low as 10-3-10-4 nm/pulse can be realized and such processing regimes were applied to diamond surface nanostructuring. Keywords laser ablation oxidation diamond nanoprocessing

Deep multipass cutting of bidirectional and unidirectional carbon fiber reinforced plastics (CFRP) with picosecond laser pulses was investigated in different static atmospheres as well as with the assistance of an oxygen or nitrogen gas flow. The ablation rate was determined as a function of the kerf depth and the resulting heat affected zone was measured. An assisting oxygen gas flow is found to significantly increase the cutting productivity, but only in deep kerfs where the diminished evaporative ablation due to the reduced laser fluence reaching the bottom of the kerf does not dominate the contribution of reactive etching anymore. Oxygen-supported cutting was shown to also solve the problem that occurs when cutting the CFRP parallel to the fiber orientation where a strong deformation and widening of the kerf, which temporarily slows down the process speed, is revealed to be typical for processing in standard air atmospheres.