Thermal Analysis of Multi-Pass Laser Irradiation on Fused Silica

摘要

A rough ground fused silica surface can be ground in a ductile mode by ultra-precision grinding after repairing the surface and subsurface micro cracks (SSMC) by CO_2 laser irradiation. In this paper, 2D finite element thermal analysis of unidirectional multi-pass laser irradiation on fused silica was conducted, and the simulation results were compared with the thermal analysis and experiments results of single pass laser irradiation. Thermal analysis results show that the SSMC on the ground fused silica can be repaired and surface roughness can be decreased simultaneously by unidirectinal laser raster scan with a power of 10.5 W, a scan velocity of 0.2 m/s and a scan spacing of 40μm.