为了改善全光逻辑门的相位差特性, 对全光逻辑异或门的相位差进行了研究。采用细化分段模型对量子点半导体光放大器的动态过程进行建模, 利用牛顿法和4阶龙格-库塔法求解三能级跃迁速率方程以及光场传输方程, 实现了基于量子点半导体光放大器马赫-曾德尔干涉仪结构的全光逻辑异或门; 研究了有源区长度、最大模式增益、输入抽运光功率以及输入抽运光脉冲宽度对通过干涉仪两臂探测光相位差的影响,同时讨论了探测光的相位差与输出光功率的关系。结果表明, 增大有源区长度、最大模式增益以及输入抽运光功率, 均能使探测光相位差增大; 随着抽运光脉冲宽度增大, 探测光相位差先增大而后趋于平缓, 之后不断减小; 有源区长度为2.0mm、最大模式增益为3000m-1、输入抽运光功率为5dBm、抽运光脉冲宽度为1.0ps时, 最大相位差增加至0.3277π; 随着探测光相位差增大, 输出光功率增大;通过优化参量可以增大探测光的相位差, 而输出光功率会随着探测光相位差的增大而增大。该研究为提高转换信号质量提供了参考。

In order to optimize the phase difference of the all-optical logic gates, the phase difference of all-optical logic exclusive OR (XOR) gates was studied. Firstly, the refined sectionalized model was used simulate the dynamic process of quantum-dot semiconductor optical amplifier (QD-SOA). Secondly, the Newton method and the four-order Runge-Kutta method were used to solve the three-level transition rate equations and the light field transfer equations. Finally, an all-optical logic XOR gate based on quantum-dot semiconductor optical amplifier Mach-Zehnder interferometer (QD-SOA-MZI) was implemented. The influence of the length of the active regions, the maximum modal gain, input pump power and input pump pulse width on phase difference of probe signal through two arms of the interferometer was studied in detail. Moreover, the relationship between phase difference of the probe signal and output optical power was also discussed. The results show that, with the increase of the length of the active regions, the maximum modal gain and input pump power can lead to improve phase difference of probe signal through two arms of the interferometer. With the increase of input pump pulse width, phase difference of probe signal through two arms of the interferometer increases at first and then decreases. When the length of the active region is 2.0mm, the maximum modal gain is 3000m-1, the input pump power is 5dBm, and input pump pulse width is 1.0ps, the maximum phase difference of probe signal through two arms of the interferometer increases 0.3277π. Output optical power also can be improved by the increase of probe signal phase difference. Phase difference of the detected light can be increased by optimizing the parameters. Output light power increases with the increase of the phase difference of the probe. This study provides a reference for improving the quality of conversion signals.