Haelangdal Insight: Optical Communications Revolution
The real bottleneck in AI clusters is not compute but data movement. After GPU/memory, the next investment phase is 'Interconnect' emerging as the bottleneck that determines utilization and ROI. I/O (SerDes) power, heat, and physical area constraints are growing rapidly, and the solution is the evolution of optical architecture from Pluggable to LPO to CPO. The investment strategy has a 3-layer structure: (1) Core (platform definers: switch ASIC/foundry), (2) Tollgate (connectors/lasers/test equipment), (3) Transition (800G/1.6T volumes, AEC/LPO).
Key Drivers
- NVIDIA 2026 CPO commercial year one + Coherent SAM $9.5B → $21B upgrade (OFC 2026)
- NVIDIA Spectrum-6 CPO + Vera Rubin NVL72 → Rubin Ultra 576-GPU domain mandate optics
- TSEM SiPho 5x expansion + NVIDIA $4B investment validates optical communications value chain re-rating
- AI cluster scale-out (100K+ GPUs) -- interconnect bottleneck emerging
- Optical architecture evolution: Pluggable to LPO to CPO
Risk Factors
- CPO mass production yield and Active Alignment process complexity
- Pluggable approach lasting longer than expected
- Network standard competition (InfiniBand vs. Ethernet vs. UALink)
- Transceiver price decline pressure and inventory adjustment cycle
Catalysts
- InP 6-inch wafer yield stabilization (2026-2027)
- Tower Q4 2025 record + NVIDIA 1.6T partnership, POET Infinity 800G H2 2026 shipment
- Broadcom Tomahawk 5 CPO (Bailly) mass production shipment
- NVIDIA Spectrum-X Photonics GTC announcement
- Marvell Celestial AI acquisition completion ($5.5B)
Value Chain Analysis
11 sub-themes
Optical Transceivers & Modules
The core of data center internal connectivity. Currently transitioning from 800G to 1.6T generation, with the high-speed optical transceiver market surging due to AI server demand explosion. Coherent has strengthened market dominance following the II-VI merger.
Silicon Photonics & CPO
Next-generation technology integrating optical components onto semiconductor chips. CPO (Co-Packaged Optics) integrates switch ASICs and optical engines into a single package, improving power efficiency by 30-40%. Mass production imminent in 2025-2026.
Optical Fiber Infrastructure
The physical backbone connecting data centers internally and externally. Meta's $6B optical fiber long-term contract signals market growth. Both data center interconnect (DCI) and internal cabling demand are growing in tandem.
Networking ASICs & Switches
The brain of AI cluster scale-out. Broadcom Tomahawk/Jericho and Marvell Teralynx dominate. 800G to 1.6T switch transition and NVIDIA Spectrum-X Ethernet-based AI fabric expansion.
Optical Components & Lasers
Core components of optical transceivers including laser diodes, optical amplifiers, and WDM filters. The high-power laser and low-power optical component market is growing with surging data center optical communications demand.
Optical Communications EMS & ODM
Specialized manufacturers of optical transceivers and networking equipment. Fabrinet is the leading player, handling contract manufacturing for Coherent, Lumentum, and others. Thailand-based low-cost manufacturing competitiveness.
AEC & LPO Silicon (Transitional)
Transitional solutions between Pluggable and CPO. AEC (Active Electrical Cable) is copper-based, supporting up to 800G/1.6T with 25-50% power savings vs. optics. LPO (Linear Pluggable Optics) reduces DSP burden for lower power. Credo leads the AEC market, sampling 1.6T AEC. 'Copper as long as possible, optics when necessary' is the industry consensus.
Optical Connectors & Interfaces (Tollgate)
The critical tollgate for CPO. Blind-Mate connectors enable connection/disconnection without direct access to optical ports, ensuring field serviceability. ELSFP (External Laser Source Form Factor Pluggable) is emerging as the standard. SENKO secured market leadership as NVIDIA's CPO partner.
Test & Measurement Equipment (Tollgate)
Combined optical-electrical testing is the key bottleneck of the CPO era. 1.6T transceiver testing requires 240Gbps/lane sampling oscilloscopes, TDECQ measurement, and simultaneous optical-electrical probing. Keysight leads with DCA-M, while Viavi and EXFO split production/field testing. ATE players (Teradyne, Advantest) are also expanding into optoelectronic testing.
CPO Packaging & Assembly
The real bottleneck for CPO is the Active Alignment process. Precision 6-DOF alignment where robots fine-tune positioning with laser feedback is essential. Process know-how that cannot be replicated by simply purchasing equipment serves as a moat. ficonTEC leads the market, while MRSI (Mycronic) pursues with sub-micron die bonding. TSMC COUPE has emerged as the de facto standard for CPO optical engines.
External Laser Source (ELS)
A key component solving CPO's thermal and serviceability challenges. By separating lasers from the ASIC package into front-panel pluggable modules, it enables thermal management and hot-swap serviceability. ELSFP (External Laser Source SFP) form factor is the standard. Lumentum leads with UHP (Ultra-High-Power) 1310nm lasers, sampling in 2026 Q1. A tollgate that is essential regardless of which platform wins.
Key Related Assets
10 stocks
Top Investment Ideas
View AllCoherent — Dominant Force in the Optical Transceiver Market
Post II-VI merger, #1 in optical transceiver and laser markets. Top beneficiary of the 800G→1.6T transceiver transition. Revenue accelerating on explosive AI data center demand. Silicon photonics and CPO capabilities secured.
Marvell — The Dark Horse of AI Networking ASICs
Specialist in networking ASICs and custom silicon. Teralynx switch ASIC emerging as a Broadcom alternative. Full AI infrastructure coverage from big tech custom AI chips (Amazon Trainium, etc.) to optical DSPs.
Corning — The Hidden Champion of Optical Fiber Infrastructure
Global #1 in optical fiber and specialty glass. Meta's $6B long-term contract puts the data center optical fiber market back in focus. Turnaround expected in optical communications from AI data center construction rush and 5G expansion.
Lumentum — Core Optical Component & Laser Supplier
Specialist in data center optical communication lasers and components. Strengths in EML/DFB lasers and optical amplifiers. Revenue growth expected from 800G/1.6T transceiver demand. Dual track with 3D sensing business.
Fabrinet — Hidden Champion of Optical Communications EMS
Specialist in optical transceiver and networking equipment contract manufacturing. Production partner for key customers including Coherent and Lumentum. Volume surging on explosive AI data center optical demand. Thailand-based low-cost manufacturing competitiveness.
Tower Semiconductor — The Undisputed Leader in Silicon Photonics Foundry
The #1 foundry for silicon photonics PIC manufacturing. Supplies SiPho chips to major optical networking firms including Coherent via the PH18 platform. SiPho revenue reached $228M (+115% YoY), with a $920M capacity expansion targeting 5x by end of 2026. Targets $2.84B revenue and 39.4% gross margin by 2028. A core infrastructure beneficiary of the CPO/1.6T transition.