<title>Ablation of ceramics by UV, visible, and IR pulsed laser radiation</title>

Abstract

Multiparametric study of A1N ceramic ablation by high intensity (I less than or equal to 10<SUP>13</SUP> W/cm<SUP>2</SUP>) nano and picosecond pulses of Nd:YAP laser have been performed. Ablation rates, surface morphology and element content, reflectivity and absorptivity of ceramic plates prior and after pulsed irradiation as well as high temperature material reflectivity have been measured. It is shown that high etch rate and good quality A1N ceramic microstructuring (cutting, hole drilling, pocket formation) can be obtained for the first, second and fourth laser harmonics if irradiation conditions are properly chosen. It was found that possibility to effectively process material, which initially weakly absorbs laser beam (first and second harmonic), it is determined by radiation and plasma induced surface modification. Comparison with other types of ceramics, such as Al<SUB>2</SUB>O<SUB>3</SUB>, Si<SUB>3</SUB>N<SUB>4</SUB>, SiC, is also made.