In 2026, per-rack power consumption in North American AI data centers is climbing at an astonishing rate. NVIDIA's Rubin architecture has pushed per-rack power consumption above 200kW, with coolant temperatures raised to as high as 45 degrees Celsius; the combination of large cold plates and microchannel technology optimizes heat exchange inside the entire system. Against this backdrop, the physical limits of air-cooling solutions have been thoroughly breached, and liquid cooling has changed from an "optional" to a "must-have."
As a core component of data center interconnection, optical modules are standing at the forefront of this cooling revolution. The XPO white paper officially released by Arista together with more than 45 industry partners proposes a new pluggable optical module standard for next-generation AI data centers. A single XPO module can provide 12.8Tbps bandwidth, integrates a liquid-cooled cold plate to support 400W+ power consumption, and achieves 204.8Tbps switching capacity within one Open Rack Unit, delivering a 4x improvement in front-panel density compared with the existing OSFP standard.
"Relying on the development of liquid cooling technology, its heat dissipation capability exceeds that of a single module," said Luo Chuaneng, CTO of HGTECH, when releasing the 12.8T XPO optical module. "This is a super pluggable optical module tailor-made for the AI era. While achieving ultra-high-bandwidth interconnection, it also solves the bandwidth and heat dissipation bottlenecks of traditional modules."
A CITIC Securities research report points out that as 800G optical modules enter large-scale volume production and 1.6T enters its first year of ramp-up, per-module power consumption and requirements for temperature control precision are rising significantly. Optical module thermal control is upgrading from a "supporting link" to a "performance-determining link."
From the perspective of the technology system, optical module thermal control has formed a three-layer architecture: chip-level precise temperature control uses Micro-TEC and ceramic substrate heat sinks; interfacial heat conduction relies on TIM gel or graphene gaskets; and module-level heat spreading is achieved through VC vapor chambers or cold plates. The 800G QSFP-DD DR8 immersion liquid-cooled optical module demonstrated on-site by Cambridge Technology at the OFC conference reduces operating temperature by at least 10°C and can reduce per-module power consumption by 0.5W to 1W. The company's world-first immersion liquid-cooled 800G OSFP DR8 optical module, using self-developed patented optical-path and liquid-path isolation technology, has already achieved volume supply.
For North American buyers, the selection of liquid-cooled optical modules needs to start from the overall data center cooling architecture. During the transition from air cooling to liquid cooling, compatibility is a key consideration—liquid-cooled modules adapted to existing OSFP and QSFP-DD packaging standards can complete cooling upgrades without changing switch cage designs. The liquid-cooled optical module market will maintain rapid growth in the coming years, and this trend has become an industry consensus.
