Ga-modified As2Se3–Te glasses for active applications in IR photonics

•Up to 3at.% of Ga can be introduced into Gax(As0.4Se0.6)100−x system.•Over 3at.% of Ga in Gax(As0.4Se0.6)100−x system provokes Ga2Se3 crystallization.•Up to 20at.% of Te can be introduced into Ga2(As0.4Se0.6)98−x−yTey system.•Ga2(As0.4Se0.6)88Te10 is the best compromise for rare earth doping and fiber drawing.•Ga2(As0.4Se0.6)88Te10 fiber doped with 500ppmw of Pr3+ shows quite low optical loses. Effect of Ga addition on physical properties of glassy As2Se3 alloys within Gax(As0.4Se0.6)100−x system (x=0–5) is studied for further improvement as rare earth ions matrix hosts. Following conventional synthesis conditions, it has been shown it is possible to introduce up to 3at.% of Ga into As2Se3 matrix without any crystallization and up to 2at.% of Ga without any changes in the properties of these alloys. The synthesized Gax(As0.4Se0.6)100−x alloys with 4 and 5at.% of Ga are partly crystallized by cubic Ga2Se3 crystallites. Tellurium has been introduced in the selected Ga2(As0.4Se0.6)98 glass following the Ga2(As0.4Se0.6)98−yTey cut-section to lower phonon energy and enhance quantum efficiency of the incorporated rare earth ions. The Ga2(As0.4Se0.6)88Te10 glass composition is the richest in Ga and Te, keeping its vitreous state without any crystallization. It has been successfully doped with 500 and 1000ppmw Pr3+ and drawn into optical fiber possessing low attenuation in mid-IR region. Emission in mid-IR was efficiently recorded by pumping Pr3+: Ga2(As0.4Se0.6)88Te10 glasses at 2μm.