12W laser amplification at 1427nm on the ^4F_3/2 to ^4I_13/2 spectral line in an Nd^3+ doped fused silica optical fiber

optical transition, low absorption of pump light from the cladding and high spectral attenuation in the 1350-1450nm range. Future fibers that mitigate these issues should lead to significant improvements in the efficiency of the laser amplifier, though the shorter wavelength region of the transition from 1310nm to >1350nm is still expected to be limited by excited state absorption.