50-kW, 100-fs pulse generation by large-mode-area erbium-ytterbium-doped photonic-crystal fiber amplifier

A high-energy femtosecond fiber amplifier using a large-mode-area single-mode erbium-ytterbium-codoped photonic-crystal fiber is presented. 700-fs pulses at 1557 nm were amplified and compressed to near-transform-limited 100-fs, 7.4-nJ pulses with >50-kW peak powers without chirped-pulse amplification.