Picosecond pulse amplification in a core-pumped large-mode-area erbium fiber

摘要

Amplification in a single-clad, large-mode-area erbium fiber as an alternative to double-clad Er-Yb amplifiersis presented. Both signal and pump are coupled through a mode-matched splice into the fundamental mode, which ensures preferential gain in the fundamental mode while minimizing the amplified spontaneous emission (ASE). The 875 (mu)m~(2) effective area of the Er fiber enables amplification of 6 ps pulses at 1.55 (mu)m wavelength by approx33 dB in a single stage to >25 kW peak power with low nonlinear pulse distortion and a diffraction-limited output beam with M~(2) < 1.1.