Investigation of the modification intensity and distribution in silica glass via ultrafast laser direct writing

In ultrafast laser processing of silica glass, the laser-affected zone and heat accumulation of the ultrafast laser influence the modified intensity and distribution within the materials, subsequently affecting its optical, mechanical, and chemical properties. Although there have been some studies on the modification of silica glass, there is still a lack of detailed research on the relationship between laser parameters and the intensity and distribution of the modification. In this study, the effects of pulse energy densities and the number of burst modes on the intensity and distribution of silica glass modification were quantitatively investigated using a combination of Raman spectroscopy detection and simulation. The results indicated that as the pulse energy density increased, the modification intensity at the bottom of the groove after laser scanning was approximately 14% higher than that at the surface. When the pulse energy density was 314J/cm 2 and the burst number was two, the internal modification intensity and distribution in silica glass exhibited a decreasing trend along the modification line region, with the modification intensity decreasing by an average of approximately 62%. This study enhances the ability to predict the intensity and morphology of ultrafast laser modified silica glass and provides theoretical guidance for preparing various silica glass components.