Every GPU-to-GPU hop in a modern AI cluster runs over fiber, and every fiber link needs laser sources, modulators, receivers, connectors, and the silicon and networking equipment to drive them. As hyperscalers move from 800-gigabit to 1.6-terabit links and build massive AI fabrics, the optical and networking layer has become a genuine bottleneck — not a commodity.
This theme tracks the companies that sell into that bottleneck across the full stack: lasers, transceivers, optical components, fiber, connectors, networking equipment, and test & measurement.
Why it matters
- Power, not just bandwidth. Copper cannot carry the distances and speeds needed inside 100k-GPU fabrics without melting the power budget. Optics win by default at scale.
- The laser is the choke point. 200G-per-lane EMLs are the single hardest part to make, and qualification cycles run 12–18 months, so incumbents enjoy real pricing power.
- Second leg: optical circuit switching. Hyperscaler-driven OCS backlog is moving from pilots to real quarterly revenue — a second growth vector on top of transceivers.
- Network complexity is rising. AI fabrics need more sophisticated routing, switching, and transport — driving demand for networking equipment and photonic components beyond just the transceiver.
Roster
- LITE — Lumentum Holdings — sole-source supplier of 200G-per-lane EMLs. NVIDIA strategic preferred investment at $695.31 on March 2, 2026.
- CIEN — Ciena — optical networking systems and WaveLogic coherent DSP for metro, long-haul, and data center interconnect.
- COHR — Coherent — broader photonics platform with silicon-photonics capability. Also received NVIDIA investment alongside LITE.
- GLW — Corning — optical fiber and cable, plus specialty glass. The physical infrastructure layer that everything else rides on.
- MTSI — MACOM Technology Solutions — high-speed analog, laser drivers, and TIAs used in 800G/1.6T transceiver modules.
- SMTC — Semtech — CopperEdge and optical PHY franchise for short-reach links inside data center racks.
- VIAV — VIAV Solutions — optical test & measurement, network monitoring, and anti-counterfeiting solutions.
- LASR — nLIGHT — industrial and defense lasers with adjacent datacenter exposure as the laser market develops.
- NOK — Nokia — IP routing, optical transport, data center switching, and programmable telecom networks for AI bandwidth build-out.
- APH — Amphenol — high-speed fiber optic and electrical connectors, including data center and AI infrastructure interconnects.
What to watch
- 200G EML mix at LITE and COHR — rising share = rising gross margin.
- Indium-phosphide capacity ramps — yield and timing determine whether scarcity holds.
- OCS backlog conversion — $400M+ of LITE backlog turning into quarterly revenue.
- Silicon photonics competitive progress — the long-dated risk to the EML franchise.
- Hyperscaler capex commentary — any pause changes the pricing regime overnight.
- 800G-to-1.6T transition timeline — drives upgrade cycles for transceivers, DSPs, and networking gear.