The real bottleneck in AI data centers isn't a single chip, but the entire photonics supply chain that converts electrical signals to optical and moves massive data. Brian, a former procurement expert from Amazon and Target, explains that as the industry upgrades from 800G to 1.6T and 3.2T, the biggest gains flow to essential suppliers like Corning, Amphenol, Ciena, and upstream materials and testing companies. This article breaks down the complete photonics chain and highlights high-growth stocks to watch.
Copper Hits a Physical Limit, Photonics Becomes Inevitable
“Copper is hitting a physical limit, and every data center will eventually have to shift to light. China has shown the industry that this path can go much further,” Brian emphasized. Once data transmission distance exceeds about 3 feet, copper cables rapidly lose advantage due to higher heat and power consumption, while light solves these issues simultaneously. The shift from electricity to light is the core significance of photonics technology.
Investment opportunities often cluster in the supply chain rather than headline-grabbing companies. “As long as a new technology is proven viable, the biggest wealth tends to flow first to companies that all participants must rely on, not just the single name that makes the headlines.” Glass, lasers, connectors, materials, and testing equipment are all essential — this is where the photonics chain holds the most value.
Corning: The King of the Glass Layer
Corning's optical communications revenue grew 36% last quarter, but segment profit surged 93%, demonstrating simultaneous pricing power and scale benefits. It has become a designated core supplier for Meta, Amazon, Google, Microsoft, OpenAI, and Nvidia — no other competitor globally has such a client list. These relationships have translated into multi-year locked-in revenue: Meta committed up to $6 billion, Amazon signed multi-billion-dollar contracts, and two other hyperscale clients signed similar agreements, all secured years before fiber is actually drawn.
Corning's latest fiber generation can pack about twice the number of cores into the same physical space compared to standard cables, and its bend-resistant glass is hard to replicate. Combined with the world's largest fiber factory and U.S. supply compliant with “Buy America” rules, it builds a strong moat. Industry fiber demand grows 22%-25% annually, but new supply capacity is only about half that rate, pushing lead times beyond 60 weeks. Currently, Corning trades at a PEG near 3 and a price-to-sales ratio of about 9x — not cheap, so waiting for a pullback is more prudent.
Interconnect Layer: Amphenol and Credo
Amphenol is a low-key giant specializing in high-speed connectors and cable assemblies covering both copper and optics. In January it acquired CommScope's fiber connectivity business for $10.5 billion, instantly becoming a significant fiber player. Its AI data center business is now the largest single segment, with organic growth exceeding 80% last quarter. Its backlog hit a record $9.4 billion, and new orders continue to outpace shipments. Operating margin expanded from 22% to nearly 28% despite the large acquisition — a sign of excellent operational integration. Valuation is reasonable: PEG around 0.7, price-to-sales ratio about 7x.
Credo Technology acts as a bridge between the old and new worlds: it uses low-power chips to extract maximum performance from copper within racks while also extending into optical communication. It recently acquired a silicon photonics company to complete its 1.6T end-to-end product stack and has shipped to all top five U.S. hyperscale cloud providers. Quarterly revenue rocketed from $135 million to $437 million in six quarters (more than tripled). Gross margin stands at 68% — more like a software company — and operating margin nearly doubled to 37%. Revenue guidance for next fiscal year still exceeds 80% growth. However, risk is extreme: just three customers account for 88% of revenue. Any slowdown from one could hammer the stock. Insiders have been selling, and the price-to-sales ratio is about 35x. PEG is near 1, but this is a high-conviction name that requires deep pullbacks to consider.
System Level and Upstream Bottlenecks: Ciena, AXT, and VEO Solutions
Ciena is the Western leader in coherent optics. Its proprietary WaveLogic technology is the first in the world to pack 1.6T data into a single wavelength, enabling capacity expansion without digging new fiber. This product alone secured 49 customers in just two quarters, and cloud clients now contribute nearly half of revenue. Backlog grew by ~$2 billion in 90 days to nearly $7 billion, almost all scheduled for delivery next year. Operating margin doubled from below 8% to over 15%, but the forward P/E of about 120x prices in perfect execution.
AXT is one of the few companies globally capable of producing indium phosphide wafers, the critical substrate for all optical lasers. Its backlog for this material exceeded $100 million, a record. But risks are front and center: almost all manufacturing is in China, requiring export licenses that impacted last quarter's revenue despite the record backlog. The company raised ~$550 million causing dilution; insiders net-sold over $70 million; it remains unprofitable, with a price-to-sales ratio of about 66x — this is a high-volatility, small-position lottery ticket.
VEO Solutions is the “pick-and-shovel” provider in optical communications — it sells test equipment that every fiber link, transceiver, and system must pass through before and during operation. It benefits regardless of which specific winner emerges. After years of stagnant revenue around $285 million per quarter, AI infrastructure buildout drove its network test business up 54%+, pushing quarterly revenue above $400 million and operating margin back to double digits. It also has a second, quieter high-margin business producing anti-counterfeit coatings for banknotes. PEG is about 1.4, but insider selling continues.
Pure Photonics ETF and Conclusion
For those who prefer not to pick individual stocks, there is now a pure photonics theme ETF (ticker: FOTO). The fund genuinely filters for pure photonics exposure, excluding diversified conglomerates. Its top 10 holdings account for nearly 90% of assets, concentrated in laser, transceiver, and photonics companies like Lumentum, Coherent, Fabrinet, IPG Photonics, and Inphi.
Brian concludes: Copper has hit its physical limit, and every data center on Earth must migrate to light. China has proven the path can go further. By combining the laser and silicon photonics companies discussed previously with today's glass, connectors, systems, and upstream suppliers, investors get a complete multi-bagger photonics supply chain map. However, many names have already rallied significantly, so the best entry points are likely after pullbacks.