At the recent OIF 448G Workshop, Peter Winzer, Founder and CTO of Nubis Communications, emphasized the urgent need for holistic electrical-optical integration as the industry approaches 448G per-lane signaling. Winzer warned that without co-optimized system design, the reliance on gearboxes will undermine the power and thermal efficiency required for the next generation of AI-driven data center infrastructure.
In a forward-looking perspective, Winzer called for modulation formats that are directly drivable—without the need for gearboxes—from high-speed electrical interfaces (SERDES), thereby minimizing power overhead and simplifying the signal path. He also noted that technologies like PAM6 or PAM8 could be viable in optical domains, but only with innovations such as low RIN lasers, optical isolators, and careful mitigation of multipath interference (MPI).
“We must think holistically. Gearbox-free architectures are essential to achieving low-power, high-density modules—whether front-panel pluggable, near-package, or co-packaged,” said Winzer. “The density doesn’t help us if we can’t cool it.”
Key Takeaways:
• Gearbox-free design is crucial for reducing power and enabling high-density optical modules.
• Linear modulation formats must be favored for direct drive from SERDES.
• Optical innovations like low-RIN lasers and isolators may be needed for PAM6/8 to succeed.
• Reliability is paramount and can only be assured with mature foundry processes—specifically silicon photonics without exotic materials.
• Driving 400G using plain silicon photonics remains a key industry milestone and opportunity.
As co-packaged optics and new high-density pluggable form factors evolve, Winzer’s message reinforces the need for tight integration and cross-domain collaboration to meet the performance, power, and reliability expectations of hyperscale computing.

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https://ngi.fyi/oif448-nubis-peter
- Nubis Communications, headquartered in New Providence, New Jersey, is a startup founded in 2020 focused on high-density, low-power optical interconnect solutions for AI and ML data centers. Its flagship XT1600 High-Density Linear Optical Engine delivers 1.6 Tbps full-duplex capacity, optimized for direct-drive operation without DSPs, reducing power and latency. The Nitro 200G Linear Redriver extends copper connections to four meters, enabling 1.6T active copper cables. Emerging from stealth in 2023, Nubis attracted investments from TDK Ventures, Matrix Partners, GV, and imec.







