A germanate glass composition suitable for use in a fiber amplifier for broadband amplification of optical signals is provided. The glass preferably includes 35-75% GeO2, 0-45% PbO, 5-20% BaO, 5-20% ZnO, and 2-10% R2O (R=Na, Li, K). It is doped with thulium ions (Tm3+) and codoped with holmium ions (Ho3+). The glass composition of results in a remarkably large bandwidth as compared with previous glasses. It is also highly compatible with existing silica optical fibers.