Washington Takes Aim at China's Grip on AI's Fiber-Optic Backbone

The components that turn electrical signals into light inside AI data-center networks became the latest front in the US-China tech fight this week. A bipartisan group of senators — Republicans John Cornyn and Dave McCormick alongside Democrats John Fetterman and Ruben Gallego — introduced legislation to bar the federal government from using Chinese-made optical transceivers in sensitive systems, naming China's Eoptolink and Zhongji Innolight directly. Running alongside it, the FCC is drafting a broader proposal to expand Secure Networks Act coverage to imports of new-model optical transceivers manufactured in China, a market where Chinese suppliers currently hold roughly 56% of global manufacturing capacity.

Wall Street's reaction was immediate and large. Coherent jumped roughly 10-11% over two sessions this week to north of $315, Lumentum rose about 9% past $1,050, and Ciena and Corning posted mid-single-digit gains, with the Roundhill Photonics & Optics ETF swinging sharply both down and up in the same week. Bernstein initiated coverage on Coherent, Lumentum, Ciena and Arista with Outperform ratings, calling optical and networking suppliers potential 'structural winners' of the AI buildout, while giving Cisco and Corning the more cautious Market Perform. Citi, separately, is modeling an $11 billion optical switching market by later this decade on the strength of scale-up networking demand from large cloud and chip customers.

The capacity problem the policy doesn't solve

The complication is that the companies best positioned to inherit Chinese market share mostly can't absorb it yet. Coherent and Lumentum are reported to already be running at or near capacity, with customer orders outstripping what they can ship by as much as 30% in some accounts of current bookings. A ban on Chinese transceivers doesn't create new fabrication capacity by itself — it reallocates scarce supply and, in the near term, likely raises prices for the optics that AI clusters depend on to move data between GPUs at scale. China also retains leverage of its own: it controls an estimated 70% of global indium phosphide supply, the material used in the lasers inside these modules, and has restricted exports of it before. A retaliatory squeeze on that input would cut directly against the US suppliers these restrictions are meant to help.

The restrictions as reported are also narrower than the stock moves might suggest. Analysts including Futurum Equities' Shay Boloor and a Morgan Stanley note both point to next-generation 3.2-terabit transceivers as the likely starting point for any rule, with phased implementation — meaning today's 800G and 1.6T AI cluster buildouts would be largely unaffected in the near term. What's really being contested is control over the interconnect layer for the generation after this one, as data-center networking shifts toward co-packaged and near-packaged optics to keep up with GPU bandwidth that copper links can no longer carry efficiently. Coherent's new PhotonLink platform, introduced in September with more than ten customer engagements in each of those two categories, is a direct bet on that transition.

That the optics trade is this volatile on headlines alone is itself a signal worth separating from the underlying demand case. Just days before this week's rally, the same stocks fell — Coherent and Applied Optoelectronics down roughly 5%, Corning off 3% — on profit-taking after Citi's bullish $11 billion TAM call, with Applied Optoelectronics up 175% year-to-date giving holders every reason to sell into strength. The secular signal is less noisy: TSMC has raised its 2026 capital spending guidance to around $64 billion explicitly citing AI chip demand outpacing its capacity, a datapoint that doesn't move on a single news cycle the way optics names do. Networking is increasingly being treated by both policymakers and analysts as its own strategic chokepoint in AI infrastructure — not just an accessory to compute — and this week showed how quickly that repricing can happen, and how little actual capacity stands behind it.