When it comes to fully photonic networking, the proposition for data center operators is an alluring one.

“There are no electrical packet switches at all,” says James Regan of the novel light-based architecture developed by his company, Oriole Networks. “So all of the switches and the transceivers connecting them, all that hierarchy is gone. Every server speaks directly to every other server, with nothing in between.”

It is not hard to see the benefits of speed and efficiency that removing so many components from what is a notoriously inefficient part of the data center could bring.

This is perhaps why more and more companies are looking to develop photonic networking systems for digital infrastructure. But whether the technology is ready to replace traditional networking architectures is another matter entirely.

Photons in the data hall

Moving information around a data center is usually heavily reliant on packet switches, which convert digital data stored on servers so that it can be transmitted as electrical signals via copper cable or fiber.

This switching process requires a lot of chips, which use plenty of power and generate significant amounts of heat. It is also inefficient, with data often having to bounce between multiple servers before it reaches its destination.

And with the amount of information flowing through data centers rising exponentially, thanks to the growth in popularity of AI systems, switching has become a pressure point for many companies.

Using photonics is seen as a potential way to alleviate this. By transmitting information using photons, vendors say they can make big efficiency and performance gains. The use of photonics in data centers is not new - DCD profiled Google’s Mission Apollo, which saw optical switches introduced to the search giant’s data centers, in 2023 - but interest in the technology has ramped up in recent months, with several vendors raising funds to develop their own particular flavors of photonics.

Oriole Networks, which spun out of the UK's University College London (UCL) in 2023, has perhaps the grandest photonic vision of all. It wants to replace the entire data center networking stack with photonic technology. As well as new networking kit, this would involve specialized software and a hardware hub to control where information is sent.

The system is “based on 20 years of research by Professor George Zervas and his team,” Regan explains. Professor Zervas is professor of optical networked systems at UCL and is one of Oriole’s co-founders. The system he designed is “not about a bit of widgetry or one particular technology,” Regan says. “It's a whole set of interlocking technologies, all of which are patented, which together make our solution.”

Regan, a photonics industry veteran who was brought on board by the Oriole founders to help bring their vision to life, believes this radical approach to redesigning data center networks is required to realize the promise of photonics.

“If you want to get the real benefits, you have to get rid of electronic packet switching completely,” he argues. “Google introduced its switches in a bunch of its data centers - they’re very slow but they allow you to reconfigure a network based on demands, and sits alongside electronic packet switching.

“What we’re doing is much more fundamental than that, because it’s designed to manage the data flows from server-to-server in an arbitrary fashion without slowing it down.”

Because of this, Oriole is touting some big benefits, in terms of efficiency but also when it comes to the time it takes to train AI models.

“When you’re training or running a large language model, you’re going backwards and forwards between GPUs all the time,” Regan says. “That’s not very efficient because most of the time the GPUs are sitting there waiting for the network to respond.”

Using photonics could remove the waiting time, Oriole claims, with GPUs able to interface with each other. Not only that, but many more interactions can take place simultaneously, speeding up the process further. This is also likely to lead to a drop in energy usage from the switching process, though, as, with GPUs available more of the time to carry out more tasks, their power consumption could rise, negating at least some of this saving.

“The power consumption is much lower because we’re removing all those switches, and that’s a lot of silicon,” Regan contends.

So far, it seems as if investors are convinced by Oriole’s vision. The company raised $32 million across two funding rounds in 2024, providing it with the cash it needs to bring its technology to market.

Photonic barriers

Oriole is far from the only company picturing a photonic future for data center networking.

US-based Lightmatter raised $400 million in December 2024 in a round that valued the company at $4.4 billion. It is marketing two photonic product lines, one of which, Passage, is an interconnect that takes arrays of processors and links them up using a programmable on-chip optical network. This takes the form of a plate, onto which chips are mounted, allowing them to make photonic data transfers.

Lightmatter hopes its latest funding will help ready Passage for mass deployment in partner data centers. Elsewhere, Xscape Photonics raised $44 million in an October 2024 funding round to develop its ChromX platform.

While investor confidence around photonics is high, the technology could still be some way off becoming a business reality. In a November 2023 research note, Omdia cloud and data center analyst Aaron Lewis described photonic computing as “an exciting technological phenomenon,” but one that has a “set of limitations that technology developers must overcome to make it worthwhile for data centers to implement them.”

These drawbacks include “complexity, cost, and compatibility concerns,” Lewis said, adding: “With further research and development, there may be possibilities for photonic components to replace electronics in the future; however, for now, electric components remain the status quo.”

For Oriole Networks, the challenge will be convincing operators to rip out tried and tested networking set-ups in favor of something completely new.

Regan is confident the benefits will outweigh the risks, and says: “You can do it a bit at a time. You can build a rack or a cluster and run ethernet over our photonic network, and it will actually connect into an ethernet network, which means you can try our system, gradually get used to it, and then upgrade.”

Having been involved with photonics since the 1980s, and previously founding two other companies operating in the space, Regan describes the progress in recent years as “mind-boggling.” He says: “Optical fiber is already in the data center, and now we’re going to the next level by taking out the electrical switches that sit between the light pipes. Once you can keep more data in the optical domain, it’s much easier to manipulate.

“We’ve put together a really strong team, experienced engineers who have been working with this kind of stuff for 20 or 30 years, they know how to do it. Now we want to move at the speed of an express train to build our product and get it out there to solve this problem.”