High Performance Erbium-Doped Fiber Amplifier Pumped at 1.48 μm and 0.97 μm

Abstract
With the growing importance of erbium-doped fiber amplifiers for telecommunications applications, considerable effort has been devoted to minimizing the pump power requirements for producing high gain. The best reported results are for λp = 0.98 μm wavelength pumping1,2 with gain coefficient up to 4.9 dB/mW, and for λp = 1.48 μm pumping,3,4 with a lower maximum gain coefficient of 2.6 dB/mW. We report here a low threshold erbium-doped fiber amplifier which, when pumped at 1.48 μm, has a gain coefficient is 5.9 dB/mW, and, when pumped at 0.972 μm, an almost equal gain coefficient of 6.1 dB/mW.