Bend-resistant fundamental mode operation in ytterbium-doped leakage channel fibers with effective areas up to 3160μm2

We report fundamental mode operation in ytterbium-doped leakage channel fibers with effective areas up to 3160 mu m(2). These fibers are bend-resistant. Lasers with slope efficiency similar to 60% and M-2 similar to 1.3 has been demonstrated. Bend loss and amplifier performance have also been characterized. (c) 2006 Optical Society of America.