Laser Writing of 2D Nanostructures in Silver-Doped Phosphate Glass

Abstract

Laser induced new optical properties in the bulk of glasses is a promising tool for photonic applications, such as optical data storage technologies, integrated photonic circuits or microfluidics based on laser-induced chemical etching selectivity. The metal-doped glasses are good candidates for direct laser writing because of the metal clusterization, formation of cluster nanostructures (NSs) and nanoparticles under irradiation and/or thermal treatment leading to the emergence of new optical properties [1]. Here we focus on the specific case of silver-doped phosphate glass irradiated by a train of femtosecond laser pulses. Silver clusterization and charge separation processes are induced in the glass by the laser irradiation, leading to the formation of silver NS and of a static electric field. This static electric field is responsible for a local centrosymmetry breakdown and the appearance of an effective second order nonlinearity in the tailored glass. The goal of this work is to describe theoretically the process of silver NS formation, space charge separation and stabilization, and subsequently the creation of second order nonlinearity in the laser-irradiated phosphate glass, to understand and to optimize this process.