Meta unveils Petal, the world’s first petabit-class transatlantic cable

If nearly three-quarters of the world streamed music all at once, it would produce an overwhelming flood of data.

Now, Meta’s new project aims to carry that vast amount of digital traffic through “glass strands” laid across 4,300 miles of deep ocean floor.

The tech giant is planning to achieve this ambitious task with Petal, its newly unveiled transatlantic subsea cable set to go live in 2029.

Petal will deliver 1 Petabit per second (1 Pbps or or 1,000 terabits per second**)** capacity across transoceanic distances. It is also said to be the world’s first petabit-class transoceanic subsea cable, connecting France and the United States.

Meta squeezes two independent light-guiding cores into a single standard glass strand to double its bandwidth. This simple redesign boosts capacity without increasing the cable’s physical size or power needs.

“We’re moving multi-core fiber from experimental to mainstream, making it a practical design for building subsea systems at scale – a shift the entire industry can benefit from. Our aim is to set a new standard for what undersea infrastructure can deliver and invite the ecosystem to invest alongside us,” the company stated.

A snapshot of a Sumitomo Electric preform of a multicore fiber strand showing two cores for light propagation. Credit: Meta.

Meta’s vision for 2029

Despite carrying nearly 99 percent of international data traffic, subsea internet infrastructure is hitting strict physical limits.

Engineers trying to support swelling AI workloads, video streaming, and cloud services often add thicker cables with more fiber pairs. More fibers mean heavier cables, larger ships, and dangerously high operating voltages.

Meta’s solution was to stop adding more cables and start redesigning the glass itself.

It chose a 2-core fiber technology in a 24-fiber-pair system for Petal, achieving the equivalent of 48 fiber pairs. The method could double the capacity of its predecessor, “Anjana”, to 1 Pbps over transatlantic distances.

Although transitioning to a 2-core design presented challenges in fiber manufacturing and core performance. Engineers kept signal loss low within standard physical dimensions by using ultra-pure synthetic silica during production. They also kept cross-talk between cores nearly immeasurable through precise refractive-index tuning and counter-propagating optical signals.

Furthermore, subsea signals traveling 7,000 kilometers require about 100 repeaters to amplify digital data across the ocean bed.

Petal solves this using a single-body 96-amp repeater equipped with a specialized Fan-In/Fan-Out interface. The interface splits each 2-core fiber into two single-core fibers inside the repeater for efficient amplification, then merges them back into 2-core fibers.

With the combination of high-efficiency amplification and low-loss fiber, Petal doubles cable capacity without proportional power increases. Interestingly, the system stays within existing 18 kV power equipment limits and avoids costly requalifications of subsea infrastructure.

Collaborative effort

Meta collaborated with three key industry partners to build and deploy the Petal subsea system. Turnkey supplier NEC engineered, qualified, and manufactured the petabit-class system, including its cable, repeaters, power systems, and installation.

Sumitomo Electric Industries supplied the multi-core fiber, creating an ultra-low-loss fiber with negligible crosstalk. On the other hand, Orange serves as the French landing party. The firm manages the cable’s arrival on France’s Atlantic coast and integrates it into Europe’s terrestrial network. Together, these companies provided the specialized engineering and infrastructure needed to realize the world’s first petabit transoceanic link.

When Petal goes live on the ocean floor in 2029, it will move data faster and transform how countries connect across oceans.