Core-clad Pr(3+)-doped Ga(In)-Ge-As-Se-(I) glass fibers: Preparation, investigation, simulation of laser characteristics

Core-clad fibers on the basis of high-purity 1300 ppmw Pr(3+)-doped Ga-Ge-As-Se and 2000 ppmw Pr(3+)-doped In-Ge-As-Se-I glasses have been prepared. The minimum optical losses of the fibers are at the level of 1 dB/m in the wavelength range, where there is no influence of the praseodymium absorption. At present, it is the best result obtained for core-clad rare-earth-doped chalcogenide fibers with high dopant concentration. The fibers exhibit the broadband luminescence in the spectral range of 3.5 5.5 gm. The values of luminescence lifetime at the wavelength of 4.7 gm are within 6.5-8.2 ms closed to those for the bulk glasses obtained previously. Simulation of laser properties for these core-clad fibers in the three-level cascade scheme was carried out. The low level of optical losses experimentally achieved in these fibers is one of main criteria for development of mid-IR fiber systems. (C) 2017 Elsevier B.V. All rights reserved.