Middle infrared luminescence of Tb³⁺ in silver halide crystals and fibers

The optical absorption and the luminescence emission were investigated in AgCl_xBr_1-x crystals (0<x<1) doped with Tb³⁺ ions and in fibers extruded from these crystals. Strong luminescence emission in the middle infrared (MIR) in the spectral range 4.2-5.6 μm was observed for the first time in such crystals and fibers.¹1Butvina et al. measured MIR luminescence from AgBr_1-xI_x polycrystalline fiber. However, the emission was too weak to allow a detailed spectroscopic analysis of the luminescence spectrum.-"The middle IR luminescence of Tb³⁺ doped AgBr_1-xI_x polycrystalline fiber" by Butvina, L.N., Dianov, E.M., Okhrimchuk, A.G., Lichkova, N.V., Zavgordnev, V.N. (Conference on Lasers and Electro-Optics Europe-Technical Digest, 354pp.). Various optical parameters were calculated for the Tb³⁺-doped crystals, using the Judd-Ofelt approximation. The measured and the calculated results have indicated that these doped crystals could be used for the development of solid-state lasers or fiber lasers operating in the middle infrared.