Effect of Femtosecond Laser Irradiation on Photostability of Chalcogenide Thinfilms Within a Ge-S Binary System

The composition dependent photostability of chalcogenide thinfilms (ChTFs) within a germanium-sulfur (Ge-S, GS) binary system was investigated via subjecting a series of GS ChTGs with different Ge/S ratios to femtosecond laser irradiation at a power density in order of megawatt per square centimeter. The experimental results show that the amount of [GeS6] octahedra existing in the ChTGs is the key factor that influences their photostability. A GeS1.5 film which contains equal amount of [GeS6] octahedra and [GeS4] tetrahedra in its glass network has been discovered to possess the highest fs-laser stability, and such fs-laser resistant ChTF could be a promising substrate for manufacturing micro-nano nonlinear photonic devices that function at high pumping power.