Wet etching study of silica glass after CWCO2 laser treatment

Silica glass is one of the most important materials in optical and electronic applications. We have investigated the wet etching characteristics of silica glass in a buffered hydrofluoric acid (BHF) solution after a thermal treatment with a CW CO2 laser. The etch rate at the center of the treated region is found to increase by approximately 100% compared to the untreated glass. This shows that the fast thermal cycle experienced by glass as a result of the laser processing changes microstructure, as characterized by an increase in fictive temperature. Thermally manipulating the microstructure of silica glass with a laser may prove to be an important new fabrication technique for integrated optics. (C) 2003 Elsevier B.V. All rights reserved.