为了改善全光波长转换器的转换性能进而提高输出信号质量, 研究了波长转换器的Q因子特性。采用牛顿迭代法和四阶龙格库塔法解光场传输方程和跃迁速率方程, 分析了输入信号光功率、脉冲宽度、最大模式增益和有源区长度4个因素对全光波长转换器的Q因子特性的影响, 并将得到的结果与相同条件下的输出消光比比较。结果表明: 增大输入信号光功率, Q因子先增大后减小, 并且在－12 dBm时取得最大值8.819 dB; Q因子随着脉冲宽度的增加而不断下降; 增大最大模式增益和有源区长度, Q因子增大。在实现波长转换的基础上,优化各参数数值, 得到的Q因子达到16.680 dB,输出信号质量较好。要同时获得高的消光比和Q因子, 提高输出信号的质量, 必须选取适当的输入信号光功率、脉冲宽度、最大模式增益和有源区长度。

In order to optimize the conversion performance of all-optical wavelength converter and improve the quality of output signal, Q factor of wavelength converter was studied. Newton iteration method and four order Runge Kutta method were used to solve the transition rate equation and light propagation equations. The effects of the input signal power, optical pulse width, maximum mode gain, and length of the active layer on Q factor of the all-optical wavelength converter were also studied, and they were compared with the output extinction ratio under the same conditions. With the increasing of the input signal power, Q factor increases up to the maxima 8.819 dB which appears at －12 dBm of the input signal power, and then begin to decrease. Q factor decreases with the increasing of the optical pulse width, and increases with the increasing of the maximum mode gain and the length of the active layer. On the basis of the realization of the wavelength conversion, by optimizing the best parameter value, the value of Q factor reaching 16.680 dB is obtained, and the output signal quality is high. In order to obtain the high extinction ratio and Q factor at the same time to improve the quality of the output converted optical signal, the appropriate input signal must be selected for the optical power, pulse width, maximum mode gain, and length of the active layer.