The Globe and Mail has published a watchlist commentary on Coherent Corp (NYSE: COHR), the photonics and engineered-materials maker, arguing that the stock is “cooling off just as its AI thermal opportunity heats up.” The piece frames a recent share-price pullback against what it presents as a growing opportunity for Coherent in thermal management for AI computing infrastructure.

This is investor commentary rather than a company announcement: Coherent has not, in this item, disclosed new products, contracts, or financial targets. The interesting question the piece surfaces is a structural one — whether heat removal, rather than chip supply, is becoming the binding constraint on how densely operators can pack AI accelerators into a rack.

Executive Summary

The commentary positions Coherent as a beneficiary of a well-documented shift in data center engineering: as AI accelerators draw ever more power per chip and per rack, traditional air cooling runs out of headroom, pushing operators toward liquid and advanced thermal solutions. In that framing, companies that supply thermal components and materials sit on the critical path of AI buildout alongside — and in some respects ahead of — the chipmakers themselves.

Why it matters: Coherent is best known in AI infrastructure for optical transceivers, the laser-based modules that carry data between GPU servers. A credible second exposure in thermal management would broaden its AI story beyond optics. But readers should be clear-eyed about what this item is: a stock-watch article pairing a price decline with a thematic opportunity. The theme — thermal as a gating constraint — is real and widely corroborated across the industry. The company-specific claim — that Coherent is positioned to capture it in size — is asserted here rather than evidenced with disclosed design wins, revenue figures, or customer names.

Why Cooling Is Becoming the Binding Constraint

For most of data center history, air cooling was sufficient: fans and chilled airflow could remove the heat a rack of servers produced. AI accelerators have broken that model. Each generation of GPU draws substantially more power than the last, and operators want them packed tightly together because AI training performance depends on short, fast connections between chips. More power in less space means more heat in less space — and air, a poor conductor, simply cannot carry it away fast enough at the densities modern AI racks demand.

The industry’s answer is liquid cooling in its various forms — cold plates bolted directly to chips, rear-door heat exchangers, and immersion systems — along with the pumps, coolant distribution units, interface materials, and specialty components that make those systems work. The practical consequence is that a data center’s usable capacity is increasingly set by how much heat it can reject, not by how many chips it can procure. That is the structural insight behind the editorial framing here, and it is well supported by how hyperscalers and colocation providers are actually redesigning facilities.

Where Coherent Fits — and Where the Evidence Thins Out

Coherent’s clearest and best-documented AI exposure is optical: it is one of the major suppliers of the high-speed optical transceivers that link GPU clusters inside AI data centers, a business that scales directly with AI networking buildout. On thermal management specifically, Coherent’s heritage is in engineered materials and components — including thermoelectric cooling technology from its acquisition history and deep expertise in materials such as silicon carbide and diamond that are valued precisely for how they handle heat. That is a plausible foundation for a thermal-management business serving AI systems.

Plausible, however, is not the same as demonstrated. This commentary does not cite disclosed thermal-management revenue, named customers, or design wins in AI cooling, and none are announced in the source item. Investors evaluating the thesis should look for those specifics in Coherent’s own filings and earnings materials. It is equally worth noting that the thermal opportunity has many claimants: established cooling and power-infrastructure vendors, cold-plate and coolant-distribution specialists, and component makers are all converging on the same market, and the eventual split of value among them is far from settled.

Reading a Watchlist Piece for What It Is

The article’s hook — a stock “cooling off” while its opportunity “heats up” — is a valuation argument, not a news event. Such framing can be useful: markets do sometimes mark down a company’s shares for near-term reasons even as a long-cycle demand driver strengthens. But the same framing can dress up an ordinary pullback as a buying opportunity without establishing that the underlying business has changed. The honest read is that the macro thesis (thermal constraints on AI density) stands on broad industry evidence, while the micro thesis (Coherent as a distinct winner in thermal) rests, in this piece, on positioning rather than disclosed numbers.

For infrastructure operators and buyers, the takeaway is less about one stock and more about procurement reality: cooling capability is becoming a first-order selection criterion for sites, racks, and system vendors. Facilities designed only for air cooling face expensive retrofits, and supply of liquid-cooling components has become a schedule risk on AI deployments in its own right. Whoever the eventual share winners are, the direction of spend is not in serious dispute.

Background

Coherent Corp traces its lineage to II-VI Incorporated, a Pennsylvania-based engineered-materials and photonics company founded in 1971, which grew through decades of acquisitions — including thermoelectric-cooler maker Marlow Industries and optical-component businesses — before acquiring laser maker Coherent Inc. in 2022 and taking its name. Today the company supplies lasers, optical networking components, and specialty materials across telecom, industrial, and data center markets, with AI data center networking emerging as a headline growth driver.

The market backdrop is the rapid escalation of power density in AI computing. Each accelerator generation draws more power, and clustering them tightly is essential to training performance, pushing rack heat loads beyond what air cooling handles economically. That has turned liquid cooling and advanced thermal components from a niche into one of the fastest-moving segments of data center infrastructure spending.

Source: Coherent Stock Is Cooling Off Just as Its AI Thermal Opportunity Heats Up — The Globe and Mail watchlist commentary on Coherent Corp (COHR) and the AI thermal management market.

Goldman Sachs has identified optical networking as the next mega-trend in AI infrastructure, according to a report headline published May 12, 2026. The thesis, as framed in the headline, is that the networks stitching together AI compute clusters are becoming a defining investment theme as those clusters scale beyond what traditional electrical interconnects handle comfortably.

Executive Summary

The announcement itself is brief: a major investment bank is elevating optical networking — moving data as light over fiber rather than as electrical signals over copper — from a component-level niche to a headline infrastructure theme. That framing matters because analyst ‘mega-trend’ designations tend to shape where institutional capital, corporate strategy decks, and procurement attention flow next.

The underlying engineering logic is well established even where the report’s specifics are not public. Modern AI training clusters connect thousands of accelerators that must exchange enormous volumes of data continuously; interconnect bandwidth, latency, and power draw increasingly gate cluster performance as much as the chips themselves. Copper’s practical reach shrinks as data rates climb, which pushes more of the network — potentially including links inside the rack, not just between racks — toward optics. If Goldman Sachs is correct that this transition is a durable trend rather than a cycle, it has implications for component suppliers, network equipment makers, data center designers, and the operators who buy from all of them.

Why Copper Runs Out of Road

Inside a data center, data moves over two broad media: copper cables carrying electrical signals, and fiber-optic cables carrying light. Copper is cheap, mature, and power-efficient over short distances, which is why it has dominated in-rack connections for decades. But as link speeds climb from 400 gigabits per second toward 800G, 1.6 terabits and beyond, electrical signals degrade over ever-shorter distances — a physics problem, not a manufacturing one. Each speed generation shrinks copper’s usable reach, until links that once comfortably spanned a row of racks struggle to span a single rack.

AI clusters make this acute. Training a large model is a collective effort across thousands of GPUs that must synchronize constantly, so the network is not a peripheral — it is part of the computer. When interconnects bottleneck, expensive accelerators sit idle. That is the structural argument behind treating optical networking as a trend that compounds with AI buildout rather than a one-time upgrade cycle.

Who Stands to Benefit — and Where the Value Concentrates

An optics-heavy buildout touches a long supply chain: laser and photonic component makers, optical transceiver manufacturers (the pluggable modules that convert electrical signals to light and back), switch and networking equipment vendors, fiber and connectivity providers, and the test-and-measurement firms that validate all of it. Emerging architectures such as co-packaged optics — placing the optical conversion directly beside the switch or accelerator silicon instead of at the faceplate — and silicon photonics, which fabricates optical components using chip-manufacturing techniques, could shift value toward semiconductor players if they mature on schedule.

For data center operators and connectivity providers, the trend cuts both ways. Optics can reduce network power per bit at high speeds, a meaningful lever when power is the scarcest resource in the industry. But optical components have historically been a cyclical, margin-volatile business, and transitions between module generations have repeatedly caught suppliers with the wrong inventory. A mega-trend label does not repeal that cyclicality.

Reading an Analyst Call for What It Is

It is worth being clear about what this news is: an investment bank’s thematic designation, as conveyed by a headline, not a technology breakthrough or a customer commitment. The engineering pressures behind the thesis are real and independently observable — hyperscalers have been discussing optical scale-up interconnects publicly for years. But the report’s specifics, including any market-size estimates, timelines, or named beneficiaries, are not in the public source material, and analyst themes can outrun deployment reality. Investors and buyers should treat the designation as a prompt to examine the underlying demand signals — accelerator shipment trajectories, switch port speed transitions, transceiver order books — rather than as evidence in itself.

Background

Goldman Sachs is one of the world’s largest investment banks, and its research designations — from ‘BRICs’ onward — have a history of shaping how institutional investors frame emerging themes. Optical technology, meanwhile, has followed a steady march inward: light replaced copper first in ocean-crossing and long-haul telecom routes, then in links between data centers, then between racks inside them. The open question for the AI era is how far that march continues — whether optics displaces copper inside the rack and eventually alongside the processors themselves.

The backdrop is the largest data center construction wave in history, driven by AI training and inference demand. As hyperscalers and cloud providers commit unprecedented capital to GPU clusters, each layer of the infrastructure stack — power, cooling, silicon, and networking — has taken its turn as the perceived bottleneck and, consequently, as an investment theme.

Source: Optical Networking: The Next Mega Trend in AI Infrastructure — Goldman Sachs, a report headline published May 12, 2026, identifying optical networking as the next mega-trend in AI infrastructure.