两阶优化增强光学相位共轭技术补偿光纤非线性

Enhanced Optical Phase Conjugation Technique for Fiber Nonlinearity Mitigation by Two-Stage Optimization

采用光学相位共轭(OPC)法补偿相干光通信系统中的非线性损伤是当前光通信领域的研究热点之一。为了进一步提升OPC抑制光纤非线性的能力,针对掺铒光纤放大器的色散管理光传输链路,提出了一种优化共轭信号功率及共轭信号累积色散的两阶优化方法。理论分析表明,功率优化带来的性能增益仅与光纤的色散-衰减系数比有关。因此,以超大有效面积光纤和反色散光纤(SLA-IDF)及标准单模光纤和色散补偿光纤(SSMF-DCF)两种色散管理链路为例,对理论分析结论进行验证。数值模拟结果表明:9信道的偏振复用四相相移键控信号经过1920 km(24×80 km)的传输后,对于SLA-IDF链路,优化光强和色散后系统的最优信噪比(SNR)分别提升了3.8 dB和1.0 dB;对于SSMF-DCF链路,优化光强和色散后系统的最优SNR分别提升了0.4 dB和1.6 dB。

One of the hottest subjects in the current optical communication sector is the use of optical phase conjugation(OPC)method to decrease fiber nonlinearity.To enhance OPC's capacity to suppress fiber nonlinearity,we propose a twostage optimization strategy for maximizing the power of conjugated signals and the cumulative dispersion of conjugated signals for the dispersionmanaged optical transmission link of erbiumdoped fiber amplifiers.The theoretical analysis reveals that the performance gain brought by power optimization is only related to the dispersionattenuation coefficient ratio of the fiber.Therefore,the theoretical analysis findings are validated using two types of dispersion management connections as examples:superlargearea fiber and inverse dispersion fiber(SLAIDF)and standard singlemode fiber and dispersion compensation fiber(SSMFDCF).The numerical simulation results show that after the 9-channel polarization multiplexed quadraturephaseshift keying signal is transmitted over 1920 km(24×80 km),for the SLAIDF link,the optimal signaltonoise ratio(SNR)of the system after optimizing the optical intensity and dispersion is improved by 3.8 dB and 1.0 dB,respectively;for the SSMFDCF link,the optimal SNR of the system after optimizing the optical intensity and dispersion is improved by 0.4 dB and 1.6 dB,respectively.