Mid-infrared (3.5–5.5 μm) spectroscopic properties of Pr3+-doped Ge–Ga–Sb–Se glasses and optical fibers

Spectroscopic properties of Pr3+-doped selenide glasses and optical fibers were investigated for their mid-infrared applications in the spectral range of 3.5–5.5 μm. Optimal concentration of Pr3+ was decided, and sensitizers for improved spontaneous emission of Pr3+: (3F2, 3H6), 3H5→3H4 transition were examined. Spectral deconvolution analysis with corrected emission bands revealed effective interaction of the excited energy states. Optical fibers doped with Pr3+ were fabricated and their spectroscopic properties were measured. Pumping scheme and energy transfer mechanism of the selenide fiber were investigated and discussed for its practical use.