The patterning of Ge-B-P doped silica glass by femtosecond laser

Abstract

The high energy pulse from a femtosecond laser at 800nm wavelength was irradiated onto Ge-P-B doped SiO2 glass film used for Planar Ligthwave Circuit in optical communication network to induce physical modification (ablation) by localized lattice cooling. The physical modification includes the hillock formation by stress relaxation and ablation by localized evaporation. To evaluate the possibility for non-lithographic patterning process, plasma etching characteristics were observed and compared between irradiated and non irradiated spot. As a result, the enhanced plasma etching rate was observed at the irradiated spot. These results open new possibilities for the fabrication of two-dimensional pattern such as waveguide, Bragg grating, and photonic crystals without complex lithography process.