NVIDIA Bets $4 Billion on Light: Silicon Photonics Is Replacing Copper in AI Data Centers
As AI data centers grow to the size of stadiums, copper interconnects are hitting a physical limit. NVIDIA's $4 billion investment in silicon photonics, a technology that transmits data as light rather than electrical signals, signals the next infrastructure revolution.
DURMUS EFE KOCH
5/21/20262 min read
The infrastructure powering the artificial intelligence boom is hitting a physical wall and it is made of copper. More than half the energy consumed in AI data centers goes not toward computation, but toward moving data through copper wires. As GPU clusters scale toward millions of units and data rates climb beyond 1.6 terabits per second, copper becomes exponentially more power-hungry, thermally unstable, and ultimately insufficient. The solution, according to NVIDIA CEO Jensen Huang, is light.
Jensen Huang at GTC 2025: 'That's Where Silicon Photonics Comes In'
At NVIDIA's GTC 2025 conference in San Jose in March 2025, Huang unveiled the company's first co-packaged optics (CPO) silicon photonics networking switches, branded as Spectrum-X Photonics and Quantum-X Photonics. Speaking to the scale of the challenge, Huang described his reasoning directly: "We use copper as much as we can on scale-up, but on scale-out, where the data centers are now the size of a stadium, that's where silicon photonics comes in."
Silicon photonics is a technology that transmits data as pulses of light through photonic integrated circuits rather than as electrical signals through copper wires. By integrating photonic components directly into switch packaging co-packaged optics, NVIDIA's new switches eliminate the energy-intensive conversion steps that conventional pluggable transceivers require. The result is 3.5 times higher power efficiency, 63 times better signal integrity, and 10 times better network resilience compared with traditional methods.
NVIDIA's $4 Billion Supply Chain Investment
NVIDIA did not stop at demonstration. By March 2026, the company had moved $4 billion into the photonics supply chain, investing $2 billion each in Lumentum Holdings and Coherent Corp — two of the world's leading photonics component manufacturers. Lumentum supplies lasers for the Spectrum-X switch line; Coherent collaborates on the silicon photonics integration itself. The investments position NVIDIA as not just a buyer of photonics components but a strategic stakeholder in the companies that make them.
The NVIDIA Quantum-X Photonics InfiniBand switch is now shipping, while the Spectrum-X Photonics Ethernet switch is expected in Q3 2026. Each Quantum-X package, manufactured by TSMC using its COUPE (Compact Universal Photonic Engine) process, combines 18 silicon photonics engines, stacking 220 million transistors on top of 1,000 photonic integrated circuits and delivering an aggregate data throughput of 4.8 terabits per second.
Broad Adoption and Market Outlook
Silicon photonics adoption is already underway at hyperscale. Oracle is running 130,000 GPUs on optical links. Google, Microsoft, Meta, and Amazon are all deploying the technology in their infrastructure buildouts. The optical networking market is projected to more than triple by 2034. ASML projects $71 billion in revenue by 2030 as AI-driven chip demand accelerates — and silicon photonics is a foundational layer enabling that scale.
The transition mirrors a historical pattern: just as fiber-optic cable replaced dial-up copper telephone lines in the 1990s, silicon photonics is on track to replace electrical copper interconnects in data center networking. The difference is that this transition is being driven by the physics of AI computation — a force that is not optional, and not patient.
References
NVIDIA. (2025, March 18). NVIDIA announces Spectrum-X Photonics, co-packaged optics networking switches to scale AI factories to millions of GPUs [Press release]. https://nvidianews.nvidia.com/news/nvidia-spectrum-x-co-packaged-optics-networking-switches-ai-factories
Optics.org. (2025, March 19). Nvidia reveals plan to scale AI 'factories' with co-packaged optics. https://optics.org/news/16/3/26
Tech Insider. (2026, April 13). NVIDIA's $4B photonics play: Lumentum vs Coherent. https://tech-insider.org/nvidia-silicon-photonics-lumentum-coherent-ai-data-center-2026/
HPCwire. (2026, April 20). Inside Nvidia's silicon photonics roadmap. https://www.hpcwire.com/2026/04/20/inside-nvidias-silicon-photonics-roadmap/
