Preparation and spectral properties of Ho~(3+)/Tm~(3+) co-doped Germanium glass active optical fiber material

摘要

A series of Tm~(3+)/Ho~(3+) sensitized 65GeO_2-7BaF_2-10B_2O_3-4Al_2O_3-4ZnO_2-10Na_2O glass samples were synthesized using high temperature melting method. The spectral properties were systematically studied when Ho~(3+) concentration was 0.1, 0.3, 0.5 mol% and Tm_2O_3 changed from 0.3 mol% to 2.5mol%. Differential thermal analysis showed that ΔT was higher than 190°C, which illustrated this kind of matrix glass have better thermal stability. The absorption cross section peak height, free energy of Ho~(3+) from ~5I_8 to ~5I_7, and emission cross section were calculated according to Mc-Cumber theory. Under the excitation of 808nm laser diode, fluorescence intensity at 1954nm reached the highest value when the concentration of Ho~(3+) was 0.1mol% and Tm~(3+) was 0.7mol%. However the fluorescence intensity reduced greatly when Ho~(3+) concentration was 0.5mol% and Tm~(3+) exceeded 1.5mol%. The sensitized function and influence of different Tm~(3+)/Ho~(3+) doped ion ratios on the spectral properties were studied.