Ciena is supporting global tests and trials of 1.6 Tbps network speeds, to meet the demands of AI
OTTAWA, Canada—The current fastest intermediary of high-speed networking glimmered green, gold and silver in Helen Xenos’ hands, the result of years of research and development in Ciena’s Ottawa lab.
The printed circuit board, gleaming components and connectors of the WaveLogic 6 Extreme represent the foundation of the high-speed networking equipment in high demand by service providers and hyperscalers, as they scramble to meet the network needs of artificial intelligence.
Xenos, Ciena’s senior director of portfolio marketing, said that the company’s customers want three things: To scale their networks. To reduce their cost per bit. And to reduce power usage, or watts per bit. The WaveLogic family of coherent optical transceivers represents Ciena’s work to meet those demands, and do so in multiple form factors for different applications.
This WL6e showcase, during the company’s recent Vectors 2025 multi-week event, brought many of Ciena’s customers to the lab in Ottawa to see the company’s latest innovations in-person.
Evolving speed and capacity in networks
The speed and capacity demands ripple across networks faster and faster these days. In the late oughts, coherent optics were primarily deployed in long-haul and submarine networks, then quickly spread to metro/regional connectivity. By the mid-2010s, hyperscale cloud providers were shifting from using dark fiber from service providers and had begun to build their own custom networks. Coherent optics began to be important not only for long-haul but for DCI, or data center interconnect—eventually, over hundreds or a thousand kilometers, as demand for cloud computing began to truly take off.
In the past 20 years, Ciena has increased the data throughput carried across each wavelength from 10 gigabits to 1.6 terabits, or 160x. As Xenos explains, that means needing significantly less equipment-footprint in order to carry far more capacity, while reducing watts per bit by more than 95%. The WL6e, which supports network speeds up to 1.6 terabits per second became commercially available in the fall of 2024. Since then, a number of 1.6 TB tests and technology trials with providers ranging from Telstra to Verizon, have signaled that a new era of AI-driven network speeds (and the accompanying upgrades) is on the way.
“The rapid expansion and distribution of AI training and inferencing infrastructure is driving global investment in ultra-scalable, high-performance networks operated by both service providers and cloud providers,” said Ciena CEO Gary Smith on the company Q1 2025 call, adding that Ciena is expecting “large, long-term investment plans over many years to come” to support the delivery and monetization of AI. Recent analysis by McKinsey projects that by 2030, data centers will see $6.7 trillion worldwide in capital outlays, to keep up with the demand for compute.
Smith said that direct orders from cloud providers accounted for more than half of orders in the first quarter, and that the company had seen its “strongest back-to-back quarters of orders from service providers in over two years.” Five cloud providers were in Ciena’s top 10 customers for the quarter.
Smith specifically called out WaveLogic 6 Extreme as being “off to an incredibly strong start in the marketplace” and said that the company added 20 new WL6e customers during the first quarter of 2025 alone. At this point, they can’t get this kind of 1.6T technology anywhere else.
“We remain the only vendor in the market with a 1.6 terabit WAN solution and expect to hold that lead in this next generation of optical technology for at least two years,” Ciena CFO Jim Moyan told investors on the call.
Knitting networks and data centers together
Interconnect within data centers, between data centers and long-haul connectivity are all very different applications. As Xenos explains, submarine networks are maximized for spectral efficiency, to get the most possible capacity over a limited and precious fiber resource. In and around the data center, the priority is using is lowest amount of power in the smallest possible space—which is why smaller, pluggable designs are so important.
At the demo in Ottawa, Ciena showcased both, with the pluggable just a fraction of the size of the WL6e modem on display. The WaveLogic 6 Nano, with support for up to 800G, is expected to be commercially available in the coming weeks, with deployments in metro DCI anticipated late this year
There are hundreds of thousands of coherent pluggables being deployed in data centers today. Ciena’s first quarter 2025 results reflected its highest number of orders to date for pluggables, and the expects to at least double its revenue from pluggables during this fiscal year.
The WaveLogic 6 Nano tech also supports what the company refers to as “Coherent-Lite”, which supports 1.6T connectivity at 2-20 kilometers for data center interconnections and is expected to be available in 2026. Ciena demonstrated Coherent-Lite at this year’s OFC. That solution combines characteristics of coherent technology and IMDD, or intensity modulation direct detection, into a single product. IMDD is a simpler system design for optical communications, generally used in shorter-reach applications in the range of tens-of-kilometers, Xenos explained. It’s a legacy technology used within data centers and data center campuses—one that isn’t going away any time soon, she points out, but which is constrained in terms speed, distances and spectral efficiency.
“When you’re trying to push IMDD technology to do 1.6 TBps, 3.2 terabit per second, it really is very limited to the distance that it can achieve,” Xenos said.
Better performance over longer distances is needed—specially given the bottlenecks that data centers face in power and real estate. Today, AI customers consist of tens of thousands of GPUs that need to be connected. That is expected to grow to hundreds of thousands of GPUs in the coming year, in projects like the Stargate DC cluster in the works in Texas.
At that point, the GPU clusters take up more than one building, and perhaps more than one campus—but still need ultra-fast, high-performance connections. Coherent-Lite extends flexibilty and scaling by enabling connections over, say, 10 or even 20 kilometers, rather than one to two, Xenos explains—enabling data centers to scale.
A wall of fiber
Down one of the hallways at Ciena’s Ottawa lab, a stack of rectangular, glass windows stretch from the floor nearly to the ceiling. On the other side of each window sits spool after spool of pale, gleaming fiber, tucked tidily side-by-side. Those spools contain, in total, hundreds of thousands of miles of fiber, so that the lab can replicate physical transmission of signals without needing to use an actual network.
The demo of the WaveLogic Extreme solutions—both the WaveLogic 6 Nano pluggable supporting 800 Gbps, side-by-side with the WaveLogic 6 Extreme supporting 1.6 Tbps—is able to accurately represent their performance by setting up a testing scenario that represents a fiber connection of more than 500 kilometers. The network deployment isn’t real, but the fiber is.
Ciena’s fiber spools represent the physical reality of hundreds of thousands of miles of fiber and enable the company to replicate customer networks with the type of fibers that they have. Service provider and fiber network operator customers, many of whom visited the lab during the Vectors 2025 event, can see how Ciena products would perform in their own networks.
Building from the chip-level
While fiber and data center structures often capture the infrastructure investment headlines, high-speed networking equipment like Ciena’s enables the communications across the physical connections. The company has pushed to 1.6 Tbps with a series of innovative design choices, including what it says is the first use of 3nm CMOS for networking, as opposed to consumer applications.
It’s a multi-year process to go from formulas on white boards to code to ASICs, Xenos explains, and requires deep understanding of customer needs, years ahead of any actual deployments. But Ciena’s engineers are its unique strength, and as is their technical knowledge across a number of related but disparate areas needed to build its solutions: materials science; high-bandwidth conversions between analog and digital signals; and the ability to put in play electro-optics capable of 200 gigabaud (GBd), or 200 billion signal changes per second, to name a few.
“It’s very, very difficult to achieve that, to have the expertise to do that,” Xenos said. “We have this expertise in-house.”
Xenos emphasizes that Ciena’s manufacturing is also fabless by design, so it isn’t tied to a specific material. Its newest coherent driver modulator is based on indium phosphide, known for being particularly thermally stable; the company also implements silicon photonics.
“We can judiciously select the right technology for the design for specific applications,” Xenos said of the materials aspect.
She continued: “We couldn’t develop this if we were reliant on other people. We wouldn’t have been able to to bring this to market as early as we did. It gives us control over the design and control over time to market, to be vertically integrated.”
Xenos wrote in a blog post on WL6e earlier this year that: “Co-development of the WL6e modem design, with experts across coherent DSP, RF design, high-speed converters, electro-optics, and optical propagation all working together, has resulted in a product that ‘just works’ to deliver incredible performance, such as 1 Tb/s single-carrier wavelength across 13,500 km, something that was previously unimaginable.”
She added: “Moreover, the decades of experience and unique insights of the Ciena team was critical in ensuring that the advanced technology could be manufactured in volume, a factor just as important as achieving the high performance WL6e design.”
One wall in particular in the lab reflects those decades. Poster-sized enlargements of the layouts of multiple generations of Ciena WaveLogic chips hang on that wall, testimony to the intricacy and evolution of both the company’s technology and the complexity of modern optical communications.
The results of that work are humming and blinking away in Ciena’s lab, and making their way into high-speed networks around the world.
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