啁啾管理调制格式在高速接入网中传输分析

Transmission analysis of chirped-managed modulation format in high speed access networks

物联网、虚拟现实及人工智能等技术的发展加大了对光纤接入无源光网络带宽的需求,其中调制器成为制约无源光网络带宽的关键因素。结合了直接调制激光器和外调制器各自优势的啁啾管理激光器以产生结构简单、便于集成等特点受到了广泛关注。采用耦合速率方程理论研究了啁啾管理激光器的动力学特性,分析了40 Gbit/s啁啾管理调制格式的产生原理及时频域特性,并在高速无色散补偿接入网中与由外调制器产生的40 Gbit/s非归零调制格式进行了性能对比。结果表明,带宽为48.5 GHz的40 Gbit/s啁啾管理调制格式在1 dB灵敏度代价下所对应的色散容限为215 ps/nm,与非归零调制格式相比其无色散补偿传输距离增加了1.6倍,表现出了强的抗色散能力,在高速接入网中也体现了较高的应用价值。相关结果可为实际系统设计提供理论参考。

The developments of Internet of Things,Virtual Reality and Artificial Intelligence(AI) technology have increased the demand for bandwidth of optical fiber access passive optical network,in which the modulators have become a key factor restricting the bandwidth of passive optical network.Chirp-managed lasers,which combine the advantages of direct modulated lasers and external modulators,have attracted wide attention for their simple structure and easy integration in low speed optical access network.The dynamic characteristics of chirp-managed lasers were studied by using coupled rate equation theory.The generation principle and time-frequency characteristics of 40 Gbit/s chirp-managed modulation format were analyzed.The performance of the chirp-managed modulation format was compared with that of the 40 Gbit/s non-return-to-zero(NRZ) signal generated by the external modulator in the high speed access network without dispersion compensation.The results show that the 40 Gbit/s chirp-managed modulation format with a bandwidth of 48.5 GHz has a corresponding dispersion tolerance of 215 ps/nm at the 1 dB sensitivity penalty.Compared with NRZ modulation format,the transmission distance of chirp-managed modulation format without dispersion compensation is increased by 1.6 times,which shows a very strong anti-dispersion capability and embodies high application values in high speed access networks.Relevant results provide a theoretical reference for the actual system design.