提出了Er/Yb共掺的光纤放大器中,Yb离子仍然存在基态能级斯塔克(Stark)分裂的假设,考虑1060 nm波段辐射,利用速率方程和传输方程,结合Er/Yb共掺双包层光纤的吸收和发射系数谱,采用4阶龙格-库塔(Runge-Kutta)算法,建立了模拟Er/Yb共掺双包层光纤放大器放大自发辐射(ASE)光谱的理论模型。通过改变抽运功率和信号功率,对其前向放大自发辐射光谱特性进行了全面的分析。大信号入射时,改变抽运功率,只改变输出功率大小,输出光谱形状不变,而当信号功率足够小时,前向放大自发辐射光谱在1535 nm和1543 nm处会出现2个局部峰值,理论模拟与实验数据相符。

Forward amplified spontaneous emission (ASE) in Er3+/Yb3+ co-doped double clad fiber amplifiers is studied by use of rate equations and transmission equations model, Stark energy level splitting theory containing 1060 nm wave band radiation, Er3+-Yb3+ absorption and emission cross sections, and Runge-Kutta 4th-order method. A multi-theoretical model is founded to analyze the ASE spectrum generally by changing the pumping power and signal power. When the signal is strong enough, it only can change the output power by changing pump power without changing the spectrum figure. When the signal is small enough, two local peaks appear at the 1535 nm and 1543 nm at the ASE spectrum. The theory is validated by experiment.