Experimental demonstration of single-span 100-km O-band 4x50-Gb/s CWDM direct-detection transmission

We report on what is to the best of our knowledge the longest 50-Gb/s/lambda O-band wavelength-division multiplexed (WDM) transmission. A pair of in-house built bismuth-doped fiber amplifiers (BDFAs) and the use of Kramers-Kronig detection-assisted single-sideband transmission are adopted to overcome the fiber loss and chromatic dispersion, respectively, in a reach-extended O-band coarse WDM (CWDM) system with a channel spacing of similar to 10 nm. Through experiments on an amplified 4x50-Gb/s/lambda direct-detection system based on booster and pre-amp BDFAs, we show the superior performance of single-sideband transmission in terms of both optical signal-to-noise ratio sensitivity and uniformity in performance amongst CWDM channels relative to double-sideband transmission after both 75-km and 100-km lengths of single-mode fiber. As a result, up to 100-km reach with comparable performance at all 50-Gb/s channels was achieved without the need for in-line optical amplification. Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Automated summary

This study reports the longest 50-Gb/s/lambda O-band wavelength-division multiplexed transmission system to date. By using in-house built bismuth-doped fiber amplifiers and Kramers-Kronig detection-assisted single-sideband transmission, the challenges of fiber loss and chromatic dispersion are overcome. The experimental results demonstrate that a transmission distance of up to 100 km can be achieved on all 50-Gb/s channels without the need for in-line optical amplification.