Study of the Mechanism of Laser Etching Fused Silica Based on Barium Compound Powder Coating

Abstract

As a solid-state laser can hardly etch fused silica, we present a new method of laser etching assisted by barium compound powder coating on the upper surface of the fused silica. Powder coating in the laser beam irradiation area will transform to molten dense material that can prevent the laser beam from directly going through the fused silica. The powder surrounding the laser irradiation area allows heat preservation, which significantly improves the local temperature to close to the melting temperature and gasification temperature, allowing the fused silica to be etched. For laser etching assisted by Ba(OH)2, chemical reaction between Ba(OH)2 and SiO2 generates BaSiO3, which plays an important role in improving the corrosion rate, and the etching groove has no obvious crack. Among laser parameters, laser pulse width has greatest impact on both the depth and width of etching groove.