Photonic startup Lightmatter secures $400 million amid AI data center boom, now valued at $4.4 billion

The rise of artificial intelligence continues to fuel a growing demand for infrastructure like AI chips and data centers. This trend has led to a massive influx of capital, with venture firms betting big on AI startups. One of the latest is Lightmatter, a tech startup that’s developing photonic chips for AI.

Today, the Mountain View, California-based Lightmatter announced it secured $400 million in a Series D round to scale up the production of its photonic chips and deploy them in data centers. The company also plans to expand its team of 200 employees across the U.S. and Canada.

This funding round, which quadruples Lightmatter’s valuation to $4.4 billion, was led by new investor T. Rowe Price, with participation from existing investors like Fidelity and GV, Alphabet’s venture arm. The new funds will allow Lightmatter to ramp up production and meet the growing demand from cloud providers and AI firms, although the company has chosen not to disclose specific clients.

The funding comes at a key time, following the recent appointment of former Nvidia executive Simona Jankowski as CFO. According to CEO Nick Harris, this might be Lightmatter’s final private funding round.

“This is probably our last private funding round,” said co-founder and CEO Nick Harris. “We’ve booked very large deals. And that is the reason that this level of funding is possible. We see a future where most of the high-performance computing and AI chips very soon are going to be based on Lightmatter tech.”

The latest cash infusion comes on the heels of Lightmatter’s previous funding, which occurred less than a year ago. In total, the company has now raised $850 million. This fresh capital aims to help Lightmatter stay ahead in the race to provide efficient infrastructure for AI, as demand for more powerful and eco-friendly data centers increases—largely driven by innovations like ChatGPT.

Founded in 2017 by Nick Harris, Darius Bunandar, and Thomas Graham, Lightmatter specializes in photonic compute chips for AI, using light to improve the speed and efficiency of computing. By leveraging silicon photonics, the company’s chips perform calculations and transfer data using light, a shift from traditional methods that are attracting significant attention from tech giants.

The funding comes at a key time, following the recent appointment of former Nvidia executive Simona Jankowski as CFO. According to CEO Nick Harris, this might be Lightmatter’s final private funding round. “We’ve secured some very large deals, which made this funding possible. We see a future where high-performance computing and AI chips will soon rely heavily on our technology.”

“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.”

Although light-based computing has been a concept for a while, making it practical at scale has proven difficult. Lightmatter’s innovation, which moves beyond the limitations of Moore’s Law and traditional scaling, is paving the way for faster, energy-efficient processors that are tailor-made for the AI era.