Diode-pumped 1.7-W erbium 3-/spl mu/m fiber laser

We follow a theoretical proposal to scale the output power of the erbium 3-/spl mu/m fiber laser to the 1-W region. Ground-state bleaching and consequent ESA losses are avoided by the combination of 1) a highly erbium-doped fiber and the relatively low pump intensity present in a cladding pumped fiber with 2) an active reduction of the excitation density by energy transfer to a Pr/sup 3+/ codopant. Recently, the first investigation of the validity of this approach has led to 660 mW of output power at 2.7 /spl mu/m under diode pumping.