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 mu m. Optimal concentration of Pr3+ was decided, and sensitizers for improved spontaneous emission of Pr3+: (F-3(2), H-3(6)), H-3(5) --> H-3(4) 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. (C) 2008 Elsevier B.V. All rights reserved.