Direct laser writing of efficient effective second order nonlinear optical properties in a tailored silver-doped phosphate glass

Abstract

This last decade, femtosecond (fs) direct laser writing (DLW) has proposed an exponentially growing number of achievements thanks to the simultaneous improvements in both fs laser technologies and material sciences, leading to innovative light/matter interactions [1]. DLW has led to micro and nano-photonics demonstrations of mechanical, chemical and optical contrast in the bulk or at the surface, as differential etching solubility, new linear absorption and fluorescence or plasmonic properties, as well as dielectric phase transition [2]. Nonlinear optical contrast can also appear from third-order nonlinear response enhancement due to density contrast, as proposed for perennial high density data storage [3, 4]. DLW also showed second-order nonlinear optical properties, even in a glassy environment, either due to the localized crystallization of non-centrosymmetric nanocrystalittes [5] or to the production of a buried static space charge separation at the root of the electric field induced second harmonic generation (EFISHG) [6].