Photonic computing company Lightmatter has officially become a unicorn, raising $155 million at a $1.2 billion valuation.

The deal was led by GV, the firm formerly known as Google Ventures, and Viking Global Investors.

The funding is an extension of the Series C investment round that saw the company raise $154m in May, tripling the company's valuation at the time. In total, Lightmatter has raised $420m.

– Lightmatter

“Lightmatter is positioned to be a key driver in powering the next generation of computing systems that will further enable AI innovation,” said Lightmatter co-founder and CEO, Nick Harris.

“We are thankful for the support of our investors, each of whom share our vision of Lightmatter playing an integral role in the future of computing. By increasing speed, lowering cost, and reducing environmental impact, our technologies can continue to push the limits of what’s possible, fueling greater AI adoption and innovation,” he said.

The Boston-based organization, which employs around 150 people, specializes in photonics-enabled technologies, using light instead of electrical signals for computing. This means that its chips don’t experience the same heat or resistance as traditional chip architectures.

The company currently offers two chips: Envise and Passage. Envise has been specifically developed to support AI workloads, while Passage is an interconnect which takes arrays of traditional processors and links them up using a programmable on-chip optical network.

Lightmatter intends to use the funds to further expand its team and office presence, with headcount already having doubled since its May funding. The company plans to open a Toronto office in 2024.