色散和自相位调制消除混沌时延的数值分析

Numerical analysis of dispersion and self-phase modulation for elimination of chaotic time delay

研究单模光纤中色散与自相位调制效应对单反馈半导体激光器混沌时延的影响.仿真中通过调节单模光纤的二阶色散系数与平均入纤光功率,以控制色散和自相位调制效应.结果表明,混沌激光在光纤中的传输距离达到色散长度后,色散效应增强使混沌时延得到明显抑制,在混沌时延特征处的自相关系数值可以最快0.5 dB/km的抑制速率下降.当混沌激光在光纤中继续传输至20 km后,由于自相位调制效应累积至显著作用范围,混沌时延达到稳定抑制状态,最优抑制效果可达11.6 dB.

We mainly investigate the influence of group velocity dispersion(GVD)and self-phase modulation(SPM)in single-mode fiber on chaotic time delay signature(TDS)of single feedback semiconductor laser.In the simulation,the second-order dispersion coefficient and the average input optical power in fibers are adjusted to control GVD and SPM.The results show that after the fiber length reaches the dispersion length of the chaotic laser,the chaotic TDS caused by single optical feedback begins to be suppressed due to the significant enhancement of GVD,and then the value of the autocorrelation coefficient at the chaotic TDS descends at the fastest suppression rate of 0.5 dB/km.When chaos laser propagates about 20 km in the fibers,duo to the accumulation of SPM to the significant range of action,the chaotic TDS achieves the best stable suppression state,and the suppression effect can reach 11.6 dB.