中文摘要：

报道了一种后向泵浦的大模面积掺镱双包层光纤放大器,输出功率为1.12 W,放大后信号光的3 dB线宽为0.028 nm,并保持了输入信号光的优良光谱特性.首次从实验上深入研究了在该种放大器中,前向输出功率、后向输出功率随泵浦功率变化的规律,为更高效率和更高功率的双包层光纤放大器的研制提供了重要的实验数据.

英文摘要：

A backward-pumped large-mode-area ytterbium-doped double-cladding fiber amplifier with the highest output power of 1. 12 W was reported. The amplified signal beam had a 3 dB linewidth of 0. 028 nm at the peak wavelength of 1 058.38 nm, preserving the exceptional spectrum characteristics of the original signal beam. For the first time, the forward beam and the backward beam amplifier was experimentally investigated, which offered valuable experimental data for the further study of double-cladding fiber amplifier with higher output power and higher amplification efficiency.