Zhou Ji, Wang Haide, Feng Yuanhua, Liu Weiping, Gao Shecheng, Yu Changyuan, Li Zhaohui
Opt Lett. 2021 Jan 1;46(1):138-141. doi: 10.1364/OL.414802.
In intensity-modulation and direct-detection (IM/DD) fiber-optic communications, it is hard to pre- or post-compensate for chromatic dispersion (CD) by digital signal processing due to one-dimensional modulation and detection. In this Letter, we propose joint optical and digital signal processing to effectively compensate for CD-caused distortions for IM/DD optical systems. As a reasonable optical signal processing, negative chirp based on self-phase modulation can suppress a part of CD to take pressure off digital signal processing. Digital signal processing is designed based on the model of a dispersive channel to accurately compensate for CD-caused distortions. To the best of our knowledge, we present a record C-band 72 Gbit/s optical on-off keying over 100 km dispersion-uncompensated link (i.e., ∼1700ps/nm dispersion), achieving a 7% hard-decision forward error correction limit. We conclude that joint optical and digital signal processing is effective in dealing with CD-caused distortions to achieve a higher capacity-distance product in IM/DD fiber-optic communications.
在强度调制和直接检测（IM/DD）光纤通信中，由于一维调制和检测，很难通过数字信号处理对色散（CD）进行预补偿或后补偿。在本信函中，我们提出联合光学和数字信号处理，以有效补偿IM/DD光学系统中由CD引起的失真。作为一种合理的光信号处理方法，基于自相位调制的负啁啾可以抑制一部分CD，从而减轻数字信号处理的压力。基于色散信道模型设计数字信号处理，以精确补偿由CD引起的失真。据我们所知，我们在100公里无色散补偿链路（即约1700ps/nm色散）上实现了创纪录的C波段72 Gbit/s光开关键控，达到了7%的硬判决前向纠错极限。我们得出结论，联合光学和数字信号处理在处理由CD引起的失真方面是有效的，从而在IM/DD光纤通信中实现更高的容量-距离积。
