Surface damage mitigation of fused silica with CO2 laser

CO 2 laser with 10.6μm wavelength radiate on damage with size below 80μm. Through examining with 351nm wavelength ultra-violet, it is found the larger damage size is, the lower extent of damage threshold is enhanced. During mitigation, thermal stress resulted from short interaction time and asymmetrical temperature distribution. Radial crack generates after damage and could expand if exposed to ultraviolet laser. After annealed in an oven for 9 hours, crack in the sample was eliminated.