Femtosecond laser writing of waveguide structures in sodium calcium silicate glasses

摘要

Waveguides were written in soda lime silicate glasses with a composition of xNa_2O xCaO (1-2x)SiO_2, where x = 15 and 20, using an amplified femtosecond laser. The waveguides formed around, not inside the exposed regions. This is similar to the waveguide behavior our group first observed in a phosphate glass, Schott IOG-1, and is distinctly different from fused silica in which the waveguides are inside the exposed regions. This data supports the rapid quenching theory, i.e. that the exposed regions cool rapidly, locking in a glass structure with a high fictive temperature, with the dependence of the refractive index on the glass cooling rate determining the qualitative behavior of the waveguides.