Real-time seamless C + L band DWDM transmission based on unified optics
Yuqian Zhang, Mingqing Zuo, Dongchen Zhang, Junjie Qi, Dawei Ge, Dong Wang, Baoluo Yan, Hu Shi, Zhaolong Liao, Lei Shen, Dechao Zhang, Han Li
Abstract
A real-time DWDM transmission system based on a unified C + L-band architecture is demonstrated. The system incorporates transceiver modules, wavelength-selective switches (WSS), and distributed Raman amplifiers (DRA), all compatible with the full C + L band. A major limitation in previous C + L-band systems is the requirement for separate optical amplifiers for each band, which increases system complexity and cost. This issue is addressed by employing an erbium-bismuth co-doped fiber amplifier (EBDFA), which achieves a 20 dB gain bandwidth of 100 nm. Enabled by these unified components, a total capacity of 62.1 Tb/s is transmitted over 80 km of G.652.D fiber using 70 WDM channels, with per-channel rates up to 1 Tb/s across a seamless 87 nm optical spectrum. The prototype highlights the feasibility of unified C + L-band optics for high-capacity, spectrally efficient, and simplified optical transport networks.