48 % power conversion efficiency in a single-pump gain-shifted thulium-doped fiber amplifier

A new pumping scheme (1.2 /spl mu/m+1.4 /spl mu/m) is demonstrated for the gain-shifted TDFA, leading to record efficiency of 48% using one single pump dual-wavelength laser. This pumping scheme was implemented with a dual wavelength Raman fiber laser, giving 48% optical efficiency.