Lightmatter Raises $400M Series D; Quadruples Valuation to $4.4B as Photonics Leader for Next-Gen AI Data Centers

Amid unprecedented demand for extreme-scale data centers, Lightmatter prepares for next phase of growth

MOUNTAIN VIEW, Calif.--(BUSINESS WIRE)--Lightmatter, the leader in photonic supercomputing, announced today it has raised a $400 million Series D, valuing the company at $4.4 billion and bringing the total capital raised to date to $850 million. The round was led by new investors advised by T. Rowe Price Associates, Inc. with participation from existing investors, including Fidelity Management & Research Company and GV (Google Ventures). With this financing, Lightmatter will ready Passage™ for mass deployment in partner data centers, enabling the scaling required for sustained AI innovation.

“We’re not just advancing AI infrastructure—we’re reinventing it,” said Lightmatter co-founder and CEO Nick Harris. “With Passage, the world’s fastest photonic engine, we’re setting a new standard for performance and breaking through the barriers that limit AI computing. This funding accelerates our ability to scale, delivering the supercomputers of tomorrow today.”

The Next Frontier in Computing Infrastructure

As frontier AI models expand and training clusters surpass 100,000 XPUs, traditional electronic interconnects are becoming a critical bottleneck. These interconnects can’t keep pace with the growing need for high-bandwidth, low-latency data movement, which is crucial for scaling AI workloads. Lightmatter’s Passage technology addresses this challenge by leveraging 3D-stacked photonics chips to move data. This breakthrough dramatically increases AI cluster bandwidth and performance, while reducing power consumption. Passage, the first photonic engine to deliver IO in 3D, frees XPU shoreline to support more memory, addressing another critical bottleneck for scaling AI performance. By transforming data movement across AI clusters, Lightmatter enables systems to scale efficiently, unlocking new levels of performance and preparing computing infrastructure for the demands of next-generation AI models.

“Lightmatter has the technology, leadership, and team to bring the industry the future of computing through photonics,” said Tony Wang, portfolio manager of the T. Rowe Price Science & Technology Fund. “The demand for AI supercomputers that will power the next wave of frontier AI models is strong and growing. We’re pleased to back Lightmatter on their mission to help power AI infrastructure.”

“AI is evolving faster than anyone could have predicted, pushing the limits of data center technology,” said Erik Nordlander, General Partner at GV. “Photonics isn’t just a breakthrough; it’s the future of million-xPU data centers for AI. We’ve proudly supported Lightmatter since the beginning, and after six years, our belief in their vision has only grown stronger. Lightmatter is the definitive leader in data center photonics, and we’re excited to stand behind them as they unlock the next era of AI innovation and scale.”

Lightmatter Accelerates Expansive Growth in Line with AI Market Needs

Lightmatter’s Series D fundraise comes on the heels of the appointment of Simona Jankowski as Lightmatter’s Chief Financial Officer, the appointment of Richard Beyer and Robin Washington to its Board of Directors, and incredible customer traction. Since the company’s last funding announcement in December 2023, Lightmatter expanded its footprint with an office in Toronto and continues to grow its team.

About Lightmatter

Lightmatter is leading the revolution in AI data center infrastructure and enabling the next giant leaps in human progress. The company invented the world's first 3D-stacked photonics engine, Passage, capable of connecting thousands to millions of processors at the speed of light in extreme-scale data centers for the most advanced AI and HPC workloads.