基于量子点光放大器波长转换的啁啾特性研究

信号光的啁啾特性在很大程度上会影响量子点半导体光放大器(QD-SOA)的性能,引起传输信号的走离效应,使误比特率增高。为了改善这一特性,对QD-SOA全光波长转换器的啁啾特性进行了系统分析,基于QD-SOA的交叉增益调制效应的全光波长转换原理,采用牛顿法和4阶龙格-库塔法求解速率方程和光场传输方程,计算了注入电流、抽运光脉宽和抽运光消光比变化时QD-SOA全光波长转换器输出变换光的啁啾值。结果表明,增大抽运光脉宽、减小注入电流和抽运光消光比均可减小变换光的啁啾值,通过优化这些参量可以减小啁啾的影响,但在设计QD-SOA全光波长转换器时,要考虑抽运光消光比和变换光啁啾之间的均衡。

Theoretical study on chirp of wavelength conversion based on QD-SOA

Chirp characteristics of signal light can largely affect the performance of quantum-dot semiconductor optical amplifiers (QD-SOA), cause the walk-off effect of transmitted signal and increase the bit error rate .To improve this situation, chirp characteristics of QD-SOA all-optical wavelength converters were analyzed .Based on all-optical wavelength conversion principle of QD-SOA's cross-gain modulation (XGM), using Newton's method and 4-order Runge-Kutta method, rate equations and light field transmission equation were solved , chirp values of converted light of a QD-SOA all-optical wavelength converter were calculated with the change of injection current , pumping light pulse width and extinction ratio of pumping light .The results show that increasing pulse width of pumping light , reducing injection current and extinction ratio of pumping light can reduce the chirp value of converted light .The impact of chirp can be reduced by optimizing these parameters .But during the design of QD-SOA all-optical wavelength converters , the balance between extinction ratio of pump light and chirp of conversion light should be considered.