针对电吸收型调制器和分布反馈激光器集成光源(EAM-DFB)的光电混合特征,建立了包含自发辐射、俄歇复合、寄生效应以及隔离电阻的等效电路模型。分析了在不同驱动电流和自发辐射因子下,该模块的输出、调制及噪声特性,并与直接调制DFB作了对比。结果表明,EAM-DFB可生成超短脉冲(小于25ps);随着驱动电流的增加,输出功率增大、脉冲展宽,噪声增强且峰值点向高频移动;减小自发辐射因子和增加驱动电流均使其调制带宽增加;与DFB相比,EAM-DFB增加了少量噪声,但具有更陡峭的功率一电流特性和更大的调制带宽。
Based on the character of photoelectric mixing in electro-absorption modulator integrated distributed-feedback semiconductor laser (EAM-DFB), the equivalent circuit model including spontaneous emission, Auger recombination, parasitic efforts and isolation resistance is established. Using this model, the output, modulation and noise property of EAM-DFB for different bias currents and spontaneous emission factors are analyzed, and compared to these properties of EAM-DFB and DFB. The results indicate that EAM-DFB is capable of generating a optical pulse shorter than 25 ps; increasing bias current can raise output power and spread line-width; enhance noise; induce the peak of noise to shift toward higher frequency. It also found that either decreasing spontaneous emission factor or increasing bias current can broaden modulation bandwidth. Comparing with DFB, EAM-DFB has more rapid light-current properties and wider modulation bandwidth with little noise increasing.