中文摘要：

设计了一个带光隔离器的复合型宽带碲基掺铒光纤放大器（EDTFA），通过对该结构模型下的速率方程和光功率传输方程组的数值模拟，理论研究了EDTFA在插入光隔离器后的性能变化。研究表明，通过插入光隔离器抑制反向传输的放大自发辐射（ASE）噪声，可以有效地改善宽带EDTFA的信号增益和噪声特性。在光纤激活长度240cm、铒掺杂浓度2000ppm和前向泵浦功率200mW下，光隔离器插入在最佳位置处时，1540nm～1600nm波段内16路信道小信号增益分别提高了0.8dB～5．9dB，噪声系数降低了0.2dB～2．2dB。研究结果对于新型宽带EDTFA应用于WDM通信系统中具有理论指导意义。

英文摘要：

A compound configuration of broadband Erbium-doped Tellurite-based fiber amplifier （EDTFA） with an optical isolator is proposed in the paper. Performance analysis of EDTFA is presented theoretically by simulating numerically the rate equations and light power propagation equations with Runge-Kutta algorithm. The analysis results indicate that the signal gain and noise characteristics of EDTFA are improved effectively by means of suppressing the amplified noises of the backward propagating spontaneous emission （ASE） with the optical isolator inserted, it is shown that small signal gain Of sixteen WDM channels within 1540nm to 1600nm band is improved about 0.8-5.9dB and the noise figure is reduced about 0.2-2.2dB under the conditions of fiber length 240cm, erbium-doped concentration 2000ppm and forward pumping power 200mW. The above results will provide theoretical significance for a new EDTFA applied to WDM communication system.