Modeling and analysis of surface roughness in fused silica by CO2 laser smoothing

The research of CO2 laser smoothing fused silica to achieve smooth surface was investigated by simulations and experiments. Micro-flow smoothing of fused silica was numerically simulated. In the experiments, the influence of processing parameters, such as P (laser power), v (scanning velocity) and d (scanning path pitch) were taken into account on surface roughness (Ra) after laser irradiation. The results show that the roughness is rapidly reduced from 183.6nm to 14.27nm under P=35W, v=0.2mm/s, d=1.0mm, and thus the smooth surface is obtained. On the other hand, the raster structure will appear on the surface at inappropriate parameters (P=30W or v=0.5mm/s or d=2.0mm). The surface roughness highly influenced by raster structure ranges from ~40nm to ~140nm, 140.9nm for P=30W, 71.6nm for v=0.5mm/s, 41.3nm for d=2.0mm.