Lumai’s revolutionary optical computing technology will help AI data centres dramatically reduce costs and boost performance – while simultaneously minimising energy consumption.

The round was led by VC investor Constructor Capital, which works with visionary founders building ground-breaking companies across the deep tech sector. It was also supported by existing investor IP Group, alongside new investors PhotonVentures, Journey Ventures, LIFTT, Qubits Ventures, State Farm Ventures, and TIS Inc. Lumai will use this investment to support its next stage of growth – advancing product development, doubling its headcount, and expanding its US presence.

This investment comes at a pivotal time for the industry as power-hungry AI models and the drive to artificial general intelligence are pushing silicon-based compute to its limits. With data centre power use in the US expected to triple by 2028, consuming up to 12% of the country’s power, the time is now to address the performance and sustainability challenges plaguing the industry.

A game-changer for AI compute

Spun out of the University of Oxford, Lumai is tackling the limitations of AI compute by using optical processing to accelerate large language models (LLMs) and other transformer-based AI. Lumai has succeeded where others have failed, overcoming the scalability challenges of optical computing. Its technology processes AI’s core arithmetic operations within optical beams traveling through 3D space, bypassing the limits of silicon GPUs and integrated photonics. By utilising low-cost optical components, the PCIe form factor enables cost-effective, high-performance AI inference, positioning Lumai as a key enabler of AI’s future.

The company’s accelerator will cut AI inference costs to one-tenth of today’s top solutions. Lumai’s unique design will deliver 50 times the performance of silicon-only accelerators while using just 10% of the power required for AI in data centres, lowering both capital costs and total cost of ownership.

Tim Weil, CEO and Co-Founder at Lumai, commented: “The future of AI demands radical breakthroughs in computing. The cost of current LLMs is unsustainable, and next-generation AI won’t happen without a major shift. Lumai’s innovative optical computing design overcomes the scalability challenges that have held others back and dramatically reduces power consumption, which will drive down the cost of AI.”

Investors speak out

"Life and intelligence are a large carbon-and electron-based neural model trained over 2 billion years,” noted Dr. Serg Bell, Founder and Chairman of Constructor Capital. “Fossil fuels are a byproduct of this evolution, and they may not generate enough energy to create a better model if we continue using electron-based computation. We need more efficient, faster energy sources for the next generation of humanity's neocortex: Artificial General Intelligence. Photons are the only known choice. Lumai’s technology is a significant step forward in improving matrix multiplication, similar to the advancements quantum computers offer for other computational scenarios.”

Dr. Lee Thornton, Partner – deeptech at IP Group, added: “Having solved the challenges of optical compute to provide a low-cost, scalable solution, Lumai’s technology has the potential to transform the future of AI. We are proud to continue supporting Lumai as it embarks on the next phase of its journey.”

“Lumai isn’t just innovating – it is fundamentally reshaping the future of AI compute,” noted Ewit Roos, General Partner, PhotonVentures. “Lumai presents one of the most compelling opportunities in next-generation data centre technology, positioning it at the forefront of the AI revolution.”

This backing reflects growing confidence in Lumai’s technology and market potential. The company recently won ‘Best Overall Technology’ at the Global OCP Future Technologies Symposium and was selected in the first cohort of companies to complete Intel Ignite’s London programme. Its head of research and co-founder, Dr. Xianxin Guo, was also chosen to join the Royal Academy of Engineering’s prestigious Shott Accelerator 2024 programme, while co-founder Dr. James Spall was selected to join the prestigious Photonics 100 list for 2025.

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