下一代光接入网采用波长堆叠同时提升单波长速率的方式提升网络容量。分析了直接调制技术在下一代无源光网络第二阶段（NG-PON2）和下一代以太无源光网络（NG-EPON）中的应用前景，讨论了啁啾管理技术和功率预算提升方案，并进行了系统演示。探讨了全业务接入网共存的无源光网络中波长间串扰，提出通过编码降低拉曼串扰的影响。
To meet the fast-growing bandwidth requirement of end users, a time and wavelength division multiplexing technique is proposed to extend the network capacity. Meanwhile, the data rate of each wavelength should also be increased. In this paper, the feasibility of using DML in TWDM-PON systems is investigated, with an emphasis on chirp management and power budget improving techniques. Besides, the Raman crosstalks between the new-added and the traditional channels are analyzed with a proposed crosstalk mitigation solution based on Dicode coding.
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