Lightmatter, a pioneering company in the realm of photonic supercomputing, has announced a successful $400 million Series D funding round, bringing the company’s valuation to an impressive $4.4 billion. This latest investment round was led by new investors advised by T. Rowe Price Associates, Inc., with continued support from existing backers such as Fidelity Management & Research Company and GV (Google Ventures). This funding milestone positions Lightmatter to accelerate its next phase of growth, aiming to revolutionize AI data center infrastructure through its groundbreaking Passage™ technology.

The total capital raised by Lightmatter now stands at $850 million, with this latest infusion of funds primarily targeted toward scaling the company’s flagship technology, Passage™, for mass deployment in partner data centers. As demand for extreme-scale AI data centers grows, the company is poised to meet the challenges of next-generation AI workloads with its cutting-edge photonics solutions.

Pushing the Boundaries of AI Infrastructure with Photonics

Nick Harris, co-founder and CEO of Lightmatter, emphasized the transformative potential of the company’s technology: "We’re not just advancing AI infrastructure—we’re reinventing it. 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.”

As artificial intelligence (AI) continues to push the limits of current computing infrastructure, traditional electronic interconnects within AI clusters are increasingly unable to keep up. These bottlenecks, particularly in terms of bandwidth and latency, have emerged as critical constraints in scaling AI workloads, especially as frontier AI models expand and the number of processing units (XPUs) per cluster surpasses 100,000.

Lightmatter’s photonic technology, spearheaded by the Passage engine, directly addresses these challenges. By utilizing 3D-stacked photonics chips, Passage enables the movement of data at the speed of light, vastly increasing bandwidth and enhancing performance while simultaneously reducing power consumption. This innovative approach frees up XPU shoreline to support additional memory, mitigating yet another bottleneck in AI performance scaling.

“Photonics isn’t just a breakthrough; it’s the future of million-XPU data centers for AI,” said Erik Nordlander, General Partner at GV. “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.”

Strategic Backing and Industry Recognition

Tony Wang, portfolio manager of the T. Rowe Price Science & Technology Fund, shared his enthusiasm for the company’s future, stating, “Lightmatter has the technology, leadership, and team to bring the industry the future of computing through photonics. 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.”

This Series D funding round is more than a financial boost—it represents widespread industry recognition of Lightmatter’s leadership in photonic supercomputing. The company’s cutting-edge technology is seen as a critical enabler for the next generation of data centers, designed to handle the massive workloads demanded by advanced AI and high-performance computing (HPC) applications.

Lightmatter's Growth Trajectory

Lightmatter’s continued growth has been marked by key milestones beyond fundraising. The recent appointment of Simona Jankowski as the company’s Chief Financial Officer, along with the addition of Richard Beyer and Robin Washington to its Board of Directors, underscores the company’s commitment to scaling both its leadership team and operational capacity. The company has also expanded geographically, with the opening of a new office in Toronto, signaling its intent to grow its global footprint in tandem with its technological advancements.

Since its last funding round in December 2023, Lightmatter has demonstrated significant customer traction and continues to expand its team, preparing for the next phase of its evolution as a leader in AI data center infrastructure.

With the infusion of $400 million in new capital, Lightmatter is well-positioned to redefine the future of AI data center infrastructure. By overcoming the limitations of traditional electronic interconnects, its Passage technology is poised to support the exponential growth of AI workloads, enabling next-generation data centers to operate with unprecedented efficiency and scale.

As AI continues to evolve at a rapid pace, Lightmatter is leading the charge in delivering the supercomputers needed to power the most advanced AI and HPC workloads of tomorrow. With a solid foundation of financial backing, industry recognition, and a clear vision for the future, the company is set to play a pivotal role in shaping the next era of computing.