Optical Networks for Computing‑Power Era: Experts Interpret S+C+L‑Band Industrialization Roadmap
With continuous construction of AI large‑model infrastructure, supercomputing and AI computing centers, bandwidth demand for backbone and data‑center interconnection surges. Multi‑band S+C+L transmission is regarded as key technology to relieve fiber spectrum shortage. At ACP 2023 industry forum, experts held round‑table discussion on practical obstacles for S+C+L moving from lab to commercial deployment.
Major Industrialization Challenges for S+C+L
- Optical amplifiers: maturity of S‑band and L‑band wideband amplifiers lags behind conventional C‑band; noise figure and gain flatness need further optimization.
- Optical components: limited portfolio of wide‑band tunable lasers, filters and isolators; relatively high component cost.
- Fiber infrastructure: legacy cables are mostly G.652, which brings higher loss for S‑band; G.654.E ultra‑low‑loss fiber is preferred for new routes.
- Standards: ITU‑T and domestic specifications are still evolving; multi‑vendor interoperability requires more validation.
- CAPEX: full‑set wide‑band hardware has higher procurement cost compared with traditional C‑band systems in early phase.
Phased Deployment Suggestions from Experts
Phase 1: Technical Validation (Now‑2025)
Continue field prototype trials, improve both raman‑free and light‑raman technical paths; conduct pilot deployments mainly on newly‑built backbone fiber routes and large‑scale DCI links.
Phase 2: Small‑Scale Commercial (2025‑2027)
Drive component‑chain iteration to lower cost of wideband amplifiers and transceivers; finalize industry standards and achieve multi‑vendor interoperability.
Phase 3: Mass‑Scale Deployment (After 2027)
S+C+L gradually becomes mainstream solution for new backbone networks, tightly cooperating with 800G/1.6T/3.2T high‑speed transceivers to sustain long‑term traffic growth of computing‑power networks.
Conclusion
S+C+L is not a short‑term stopgap solution, but a primary fiber‑capacity‑expansion roadmap for the coming decade. Equipment vendors, component suppliers, operators and standard bodies need joint efforts to balance performance, power consumption and cost for steady real‑world adoption.
