Method for preparing high-purity REE-doped chalcogenide glasses for bulk and fiber lasers operating at ∼ 5μm region

Abstract

A method for preparing high purity rare earth elements (REEs) doped chalcogenide glasses, in which all components of the charge (Ge, Sb, Ga, Se) and REEs are loaded and subjected to additional purification by combining reactive distillation of germanium and antimony selenides and chemical vapor transport (CVT) of gallium and REE iodides under high vacuum conditions, is proposed. The technique is tested in the preparation of Ga5Ge20Sb10Se65 glass doped with (1–20)·1019 at·cm−3 Ce, Pr, Nd, Tb, Dy. In the best glass samples, the content of impurities was as following: metals – 0.03–4 ppm(wt), hydrogen – 0.01 ppm(wt), heterogeneous micron sized inclusions < 102 cm–3. The novel high purity level of Ce3+ and Tb3+ doped glasses made it possible to achieve reproducible practically significant characteristics of laser generation power in the 4.5–5.9 μm range in bulk samples and optical fibers in pulsed and continuous modes at room temperature.