AI Data Centers Trigger Optical Fiber Boom, Threatening Copper's Reign

For decades, copper has been the backbone of data center connectivity, but the relentless march of artificial intelligence is now threatening its dominance. According to a recent CNBC report, Nvidia is expected to replace copper cables with Corning's optical fiber in its AI rack-scale systems to reduce energy consumption and latency. This shift, driven by the insatiable bandwidth demands of AI workloads, marks a pivotal moment for the copper market and signals a new era for optical fiber.

The scale of the transformation is staggering. Data from CRU Group shows that data centers accounted for less than 5% of global optical fiber demand in 2024, but that share is projected to soar to 30% by 2027. Industry insiders estimate that AI data centers require around 36 times more optical fiber than traditional CPU server racks, as tens of thousands of chips must work in unison, generating unprecedented data transmission density. This is not merely a gradual shift; it is a structural reordering of material demand in the digital economy.

Chinese optical fiber manufacturers are already feeling the heat. Hengtong and FiberHome, two industry leaders, report that their production lines are operating at full capacity, with delivery cycles stretching from weeks to months. Orders at major Chinese manufacturers have been booked through early 2027, according to technology publication DigiTimes. The bottleneck, however, lies upstream in optical fiber preforms—the glass rods used to draw fiber. Manufacturing these preforms requires advanced technology, and adding new capacity typically takes one and a half to two years. Even as cable makers accelerate production, short-term constraints on preform supply could limit the industry's ability to meet surging demand.

The implications for copper are profound. Copper cables have long been the workhorse for intra-data center connections, but their limitations in bandwidth and energy efficiency are becoming critical as AI clusters scale. Nvidia's move to optical fiber is a bellwether: if the industry's most influential hardware maker chooses light over electrons, others will follow. This does not spell the end for copper—it will still be used in power distribution and legacy systems—but its role in high-speed data transmission is eroding.

From an investor perspective, the optical fiber boom presents a clear opportunity. Major US tech companies, including Meta, have already started locking in production capacity through multi-year supply agreements. The shift is also influencing investment allocation strategies, as capital flows toward fiber producers and away from traditional copper cable manufacturers. However, patience is required: the preform bottleneck means that supply constraints will persist into 2027, potentially driving up prices for optical fiber and benefiting early movers with secured capacity.

Original commentary: The copper market has largely been driven by macroeconomic factors like construction and electric vehicles, but the AI data center revolution introduces a new demand vector that could depress copper's growth in networking applications. While copper's use in power transmission remains robust, the high-margin connectivity segment is being ceded to fiber. Investors should watch for further announcements from hyperscalers like Google and Amazon, who may follow Meta and Nvidia in committing to fiber, accelerating the transition. The race is now on for preform capacity, and those who control this upstream bottleneck will command the market.

Sources: CNBC