Diode Pumped Laser Machining of Materials
Fig 5. SEM images of holes in ceramics, tp =35ps, l =532nm,
a) Si3N4, I=2.4*1012W/cm2, rf=6mm, d=20mm
b) Si3N4, I=1.1*1012W/cm2, rf=4.8mm, d=13.4mm
c) SiC, I=1.2*1011W/cm2, rf=3.1mm, d=5mm (R.Weichenhain, et. al., 1997)
A smaller heat affected zone in Si3N4 in case of the lower intensity Fig.a & b) is perceptible. The structure in SiC is marked by sharp edges (Fig c).