Optically homogeneous As-Se and As-S-Se glasses doped with the ions of rare-earth elements (REE), i.e. praseodymium, dysprosium and terbium up to 9000 wt. ppm were synthesized. A technique for introduction of REE into chalcogenide glasses (CG) is based on solidification of the melt of glass-forming compounds with the dopants of REE iodide and the time-temperature modes minimizing glass crystallization and dopant clustering. Microhomogeneity and absorption of the produced samples of the doped glasses were studied in the middle IR range. A spectral dependence of absorption by REE ions was investigated and the extinction coefficients were determined for the most intensive absorption bands of the ions of praseodymium, dysprosium and terbium. Luminescence properties of CG doped with Tb3+ were investigated at 4-5 mum. The optical fibers based on arsenic selenide doped with terbium were manufactured with optical losses of 1.5 dB/m at 6-9 mum and a bending strength of 0.6 GPa. (C) 2003 Published by Elsevier B.V.