Figure 2
From: Generation of Scratches and Their Effects on Laser Damage Performance of Silica Glass

Surface morphology of sample A~E.
(a) No scratches are found for sample A; (b) ductile scratches appear on the surface of sample B; (c) more ductile scratches occur on the surface of sample C; (d) ductile scratches and brittle scratches generate on sample D; (e) more brittle scratches and a vast number of ductile scratches happen on sample E; (f) increasing SiC concentration will give rise to more brittle and ductile scratches.