Tiger Ninomiya of Accelink Technologies presented at OCP Global Summit 2025 on optical transceiver technologies for AI-scale interconnects, covering DSP, LPO, LRO, and Co-Packaged Optics. The talk compared power efficiency across transceiver types with hard data — a 400k GB300 GPU cluster uses 492 MW with DSP, 480 MW with LPO (-2%), and 434 MW with CPO (-10%). Accelink demonstrated 1.6T LRO performance, ELSFP 25 dBm laser sources, and a 3.2T CPO optical engine, while also outlining the three-part roadmap required for CPO mass deployment, expected circa 2028.

Key Takeaways

• DSP optical modules consume ~49% of 51.2T switch power; CPO reduces a 400k GB300 GPU cluster's total power by 10% (492 MW → 434 MW) vs. 2% for LPO (→ 480 MW).
• DSP previously accounted for ~40% of transceiver module power; LPO eliminates it for maximum efficiency, while LRO hybridizes (DSP Tx only) to balance robustness and savings.
• Accelink validated 800G DR8 LPO BER across all 64 ports of a switch with all ports well within 1E-9, proving LPO consistency across varying port channel lengths.
• Accelink's 1.6T OSFP224 2xDR4 LRO achieved all 8 lanes well below the 1E-4 BER spec, and is extending reach to 2xVR4 (30–50 m) and 2xFR4 (up to 2 km).
• LPO MSA published 100G-DR-LPO Rev 1.0 enabling 800G interoperability; IEEE 802.3dj (224G/lane) is at Draft 2.0 targeting 1.6T and 3.2T systems.
• Accelink's ELSFP demonstrates 25 dBm optical output power — among the highest for this form factor — with 8 lasers, center wavelength 1304.5–1317.5 nm, OIF-compliant.
• CPO mass deployment requires three sequential gates: pluggable evolution/limitation recognition, CPO technology maturity (packaging, reliability, maintainability), and CPO ecosystem maturity (open interfaces, multi-vendor supply chain); LightCounting forecasts ramp from 2028.
• Accelink is pursuing 400G/lane optics using InP EAM arrays (~120 GHz 3dB BW) and TFLN modulators (~115 GHz 3dB BW) as next-generation transmitter approaches.