Photonics computing company Lightmatter has announced it's extending its manufacturing partnerships with GlobalFoundries, ASE, and Amkor.

While the company has already worked with the companies to produce its proof of concept chips, speaking to DCD at SC24, Lightmatter’s VP of product, Steve Klinger, said the announcements reinforce the fact that Lightmatter is moving into the next phase of its product development.

Lightmatter SC24
– Charlotte Trueman

Describing ASE as one of the “premier packaging suppliers in the industry,” Klinger said the company is one of Lightmatter’s key OSAT (outsourced semiconductor assembly and test) partners. Meanwhile, Lightmatter is also working with Amkor on the packaging front for very large-scale package complexes for its Passage optical interconnect.

Referencing Lightmatter’s “collaborative partnership” with GlobalFoundries, Klinger said the two companies have worked together previously on tape outs but Lightmatter has now reached the point where it is no longer building proof of concepts and is instead starting to manufacture the versions of Passage that will be available to customers in the latter part of 2025.

Lightmatter’s concept is to take compute units or networking chips and build them directly onto silicon photonics. This allows the company to take a die from a customer who is already developing a high bandwidth networking chip and integrate it directly with Lightmatter’s Passage interconnect.

“The benefit of doing that is we can do the electrical optical conversion immediately, right underneath the signal bump on the die, so it's very efficient. But, the more important thing is, because it's a 3D integration, you can locate the high-speed signals on the customer die anywhere in the area of the chip.”

This allows for improved escape bandwidth, the data transfer rate at which information can leave a computing component and connect to other components outside of its package, while also increasing the number of ports that can be connected to adjacent compute units or networking chips.

Klinger said one of the advantages of working with GlobalFoundries is that its manufacturing process allows for both transistors and photonics on the same chip. This means that all of the control circuitry for the photonics is inside Passage, the benefit of which is if a customer has already designed a chip it wants to integrate with Passage, the chip’s top side design doesn’t have to be modified.

He explained that Lightmatter works closely with customers to develop the most optimal design to leverage Passage but won’t turn away those who haven’t collaborated with the company. However, Klinger noted that the difference between a chip that has been optimized for Passage compared to one that has not could be “quite significant.”

Founded in 2017, Boston-based Lightmatter specializes in photonics-enabled technologies that use light instead of electrical signals for computing, meaning its chips don’t experience the same heat or resistance as traditional chip architectures.

The company currently employs 210 people across North America and, to date, has developed two chips: Envise and Passage. Envise is a general-purpose photonic accelerator been specifically developed to support AI workloads, while Passage is an interconnect that takes arrays of traditional processors and links them up using a programmable on-chip optical network.

Klinger said Lightmatter’s founders saw an opportunity to commercialize silicon photonic-based products when they were working on quantum technologies at MIT. He explains that the company initially built a working photonic computer to run machine learning models but ultimately decided that wasn’t necessarily going to be a product it could commercialize.

“It was a pretty important achievement and it also laid the groundwork for our interconnect initiative,” he said. “Now, the problem we're trying to address is to help continue compute scaling, in particular, AI compute scaling by breaking the bottleneck in the interconnect… because the bottleneck is essentially killing performance in AI training.”

Lightmatter’s chips haven’t been deployed by customers yet but Klinger said the products are expected to hit the market in the latter part of next year.

To date, the company has raised $850 million and in October it received a $4.4 billion valuation after closing a $400m Series D funding round. Klinger said the fundraising has allowed the company to grow its employee base and continue along its product roadmap; further developing the technology and engaging with more customers.

“There's huge growth in photonics right now. Every large company has some initiative around it right now, and I think it's also that the maturity of the technology is at the right point. There’s a market need, you can't keep scaling with pure electrical interconnects… so yes, we're very bullish. We think this is a huge market.”