放大自发辐射(ASE)是限制铒镱(Er-Yb)共掺光纤放大器功率提高的一个重要因素。采用数值仿真的方法，对高功率抽运Er-Yb共掺双包层光纤放大器中ASE的影响及其抑制措施进行了研究。研究结果表明,与抽运反向的Yb波段ASE是导致高功率抽运下放大器效率下降的主要原因，它的影响表现出明显的阈值特性；后向抽运方式的效率比前向抽运高且其Yb波段ASE的阈值更高；在放大器中同时输入一与抽运同向的合适波长的Yb波段信号，可以有效地抑制高功率抽运下抽运反向Yb波段ASE的产生，从而显著地提高放大器的抽运转化效率。

Amplified spontaneous emission (ASE) is an important factor that limits the output power of Er-Yb co-doped fiber amplifiers (EYDFs). The impact of ASE on the performance of high power pumped EYDFs is investigated numerically and a new method for ASE suppression is proposed. The results show that the counter-pump Yb-band ASE is the principle cause that drops down the slope efficiency of an EYDF at high pump power and its impact exhibits an evident threshold pump power; The efficiency and the ASE threshold pump power of backward-pumped EYDFs are higher than those of forward-pumped ones; By inputting an Yb-band signal of proper wavelength in the same direction of the pump, the counter-pump Yb-band ASE can be effectually suppressed and thus the pump-conversion-efficiency of the amplifier can be dramatically improved.