Emission of 1.38 μm and gain properties from Ho^3+-doped low-phonon-energy gallate bismuth lead oxide glasses for fiber-optic amplifiers

Efficient emission at 1.38 μm wavelength from holmium (Ho^3+)-doped low-phonon-energy gallate bismuth lead (GBL) oxide glasses, owing to the Ho^3+: (^5S_2,^5F_4)?^5I_5 transition, was observed, and the stimulated emission cross section was calculated to be 2.4×10^−21 cm^2. Population inversions between the (^5S_2,^5F_4) and ^5I_5 levels have been achieved, and a broad gain bandwidth from 1350 to 1450 nm was obtained. The large product of emission cross section and measured lifetime also support this characteristic. The results indicate that a Ho^3+-doped GBL glass system is a promising candidate for the development of E-band (1360-1460 nm) fiber-optic amplifiers.