摘要
为了降低全光波长转换器的转换出错率进而提高输出信号的质量,文章对全光波长转换器的误码率(Bit error rate,BER)进行研究。基于交叉增益调制型(Cross gain modulation,XGM)量子点半导体光放大器(Quantum dot semiconductor optical amplifiers,QD-SOA)的结构建立静态、动态模型,采用牛顿迭代法和四阶龙格-库塔法求解速率方程和光场传输方程来分析后端面反射率、有源区长度、泵浦光功率、从浸润层到激发态的弛豫时间和注入电流密度五个因素对单端耦合下QD-SOA误码率的影响。结果表明,减小后端面反射率,增大注入电流密度,增大有源区长度,减小载流子从浸润层到激发态的弛豫时间,增大泵浦光功率均可减小误码率。为降低波长转换的出错率,提高输出信号的品质,必须选取适当的后端面反射率、有源区长度、泵浦光功率、弛豫时间和注入电流密度。计算显示单端耦合与双端耦合的误码率相差不大,但单端耦合较双端耦合具有制作工艺简单,输入功率动态范围更大的优势,故在一定条件下可选用单端耦合的QD-SOA。
In order to reduce the error rate and improve the quality of the output signal, the bit error rate （BER） of the wavelength converter is studied. A single-port-coupled quantum dot semiconductor optical amplifier （QD-SOA） structure of all-optical wavelength converter based on the wavelength of the QD-SOA cross gain modulation （XGM） conversion principle is studied. The rate equations and the light field transmission equations are solved by utilizing the Newton method and forth-order Runge-Kutta method to analyze how the length of active region, pump power, relaxation time from wetting layer to excited state and the injection current density influence the bit error rate （BER） of single-port-coupled all-optical wavelength converter. The results show that increasing injection current density, increasing length of active region, decreasing carriers＇ relaxation time from wetting layer to excited state, and increasing pumping power can reduce the bit error rate （BER）. Appropriate length of the active region, pump power, relaxation time and injection current density must be selected to decrease the error rate of wavelength conversion and improve the quality of the output signal. The difference between the BERs of single-port-coupled and double-port-coupled QD-SOA is minor, but the single-port-coupled can effectively improve the output extinction ratio characteristics. Furthermore, the single-port-coupled structure has the advantages of simple manufacturing operation and greater dynamic range of input power. It is an improvement compared to the double-port-coupled QD-SOA.
出处
《电子技术（上海）》
2016年第9期8-13,共6页
Electronic Technology
