Rare-earth doped selenide glasses and fibers for active applications in the near and mid-IR

Glasses based on the composition Ge16.5As18.5Ga0.5Se64.5 doped with Pr3+ and Dy3+ were investigated for active applications in the near and mid-IR. Pr3+ has been investigated and mid-IR emission in the 3-5 mu m region has been observed. Dynamic distillation and sublimation were performed on Se and As respectively to reduce the oxide and hydrogen related impurities in the glass. These techniques resulted in the elimination of oxide impurities and resulted in about a 10-fold reduction in hydrogen related impurities compared to the as-received chemicals. Spectroscopy performed on Dy3+ resulted in a measured quantum efficiency for the (F11/2/H9/2)-F-6-H-6 level of 94% with a branching ratio of 90% for the 1.3 mu m transition and a calculated emission cross section (sigma(e)) for this transition of 2.7 x 10(-20) cm(2). Core only glass doped with 400 ppm Dy3+ has been fiberized. The losses were 0.8 dB/m at 6 mu m and 1.5 dB/m at 2.5 mu m as measured by a cutback technique. Single mode Dy3+ doped fiber has been drawn via double crucible techniques. The fiber had a 4 mu m core with a 110 mu m clad and had a core loss of 3 dB/m measured at 1.55 mu m (C) 1999 Elsevier Science B.V. All rights reserved.