Nonlinearity Mitigation of Multi-Level Optical Transmission Using Spectrum-Split Digital Pre-Distortion

• Published in: IEEE Photonics Journal
• Main Authors: Gyu-Tai Lim, Hyoung-Joon Park, Sang-Kook Han
• Format: Article in Journal/Newspaper
• Language: English
• Published: IEEE 2020
• Subjects: Linearization techniques; nonlinear distortion; optical fiber communication; predistortion; Applied optics. Photonics; TA1501-1820; Optics. Light; QC350-467; DML
• Online Access: https://doi.org/10.1109/JPHOT.2019.2959002; https://doaj.org/article/dad767d2f4d443169e52c70528a3036f

To overcome the frequency-dependent nonlinear characteristics of a directly modulated laser (DML) in a multi-level optical transmission, the spectrum-split digital pre-distortion (SS-DPD) is proposed and experimentally demonstrated to mitigate the frequency-dependent nonlinear impairments. The SS-DPD is employed in a 5 Gb/s PAM-4 optical transmission using a DML over a 5 km standard single-mode fiber at 1550 nm. We experimentally compared the SS-DPD with the DPDs based on the Volterra series and the memory polynomial (MP). The results demonstrate that the SS-DPD improved approximately 1 dB in terms of the receiver sensitivity compared with the MP-DPD. Moreover, the SS-DPD achieves 0.4 dB receiver sensitivity gain compared with the Volterra DPD.