提出了一种高速率、偏振复用、正交幅度调制信号的色散平坦光纤传输系统, 传输速率分别为160 Gbps和256 Gbps, 调制格式为PM-16QAM。实验研究了色散平坦光纤链路系统的传输特性, 并分别与非零色散位移光纤和标准单模光纤链路传输特性做了比较。实验结果表明, 较低输入光功率情况下, PM-16QAM信号在160 Gbps传输50 km时, 经色散平坦光纤传输后的误差矢量幅度EVM优于经非零色散位移光纤传输情况0.5%, 比特误码率BER优于非零色散位移光纤传输情况两个数量级; 色散平坦光纤链路能更好地衰减旁瓣噪声; 256 Gbps传输50 km和75 km时, 仅在色散平坦光纤链路传输后可以较好地解调出信号; 传输距离越长, 保持较好特性时输入光功率范围越小。对比160 Gbps和256 Gbps情况, 高速率PM-16QAM信号在色散平坦光纤链路的传输特性优于非零色散位移光纤和标准单模光纤链路的传输特性, 传输速率越高、传输距离越长效果越明显。

A dispersion flattened fiber (DFF) transmission system was proposed with high bitrate, polarization multiplexing and quadrature amplitude modulation(QAM) signal. The modulation format of the system was PM-16QAM, the bitrates were 160 Gbps and 256 Gbps. The transmission characteristics over DFF link system were experimentally studied, which were compared with those of non-zero dispersion shifted fiber (NZDSF) link and standard single mode fiber (SSMF) link. The experimental results show that the Error Vector Magnitude (EVM) of 160 Gbps and PM-16QAM over 50 km DFF link is 0.5% better than those over 50 km NZDSF link, the BER is 2 orders of magnitude better than that of NZDSF, and the DFF link can better reduce side-mode noise. When bitrate is 256 Gbps and transmission distance are 50 km and 75 km, the PM-16QAM signal can be well demodulated only after the DFF link. And the longer the transmission distance, the smaller the input optical power range is while maintaining good characteristics. Comparing 160 Gbps with 256 Gbps, high bitrate PM-16QAM signal transmission characteristics over the DFF link are superior to those over NZDSF and SSMF links. The higher the transmission rate and the longer the transmission distance, the more obvious the transmission effects are.