US Stock Optical Module Explained: A Complete Breakdown of the Seven-Layer Industry Chain

Layer 1: Raw Materials

• Positioning: I. The "Foundation" of the Entire Industry Chain

• Core Function: Provides the core raw materials for manufacturing optical chips, the physical basis for all optical devices

◦ $AXT(AXTI.US): A leader in compound semiconductor substrates like Gallium Arsenide, Indium Phosphide

◦ $IQE: IQE plc, a global leading supplier of epitaxial wafers for optical communications and laser chips

◦ $SOI: Silicon-based substrate supplier, core material for silicon photonics chips

Layer 2: Core Lasers

• Positioning: II. The Core Light Source, the "Power Plant" of Optical Signals

• Core Function: Generates optical signals, the "source" of all optical transmission and interconnection; without lasers, there is no optical communication

◦ $Lumentum(LITE.US) Global leader in laser chips

◦ $Applied Optoelectronics(AAOI.US) Supplier of data center laser transceivers and laser chips

◦ $Coherent Corp.(COHR.US): Coherent, a leader in high-power lasers and optical chips, covering data center and telecom markets

Layer 3: Manufacturing & Packaging/Testing

• Positioning: III. Foundries and Packaging, the "Processing Plant" for Optical Chips

• Core Function: Wafer fabrication, packaging, and testing of optical chips, the critical step to turn design into physical products

◦ $Tower Semicon(TSEM.US): A specialty foundry focused on manufacturing optical chips and RF chips

◦ $Fabrinet(FN.US): Hon Hai Precision, the world's largest OSAT (Outsourced Semiconductor Assembly and Test), undertaking optical device packaging

Layer 4: Digital Signal Processors & Architecture

• Positioning: IV. Signal Intelligence, the "Brain" of Optical Signals

• Core Function: Processes high-speed optical signals, enabling electrical-to-optical signal conversion, signal modulation/demodulation, core to high-speed optical modules

◦ $Marvell Tech(MRVL.US): Leader in high-speed optical DSP chips, a core supplier for 800G/1.6T optical modules

◦ $Broadcom(AVGO.US): Broadcom, global leader in optical DSP and optical interconnect chips, a core supplier for AI data centers

Layer 5: CPO (Co-Packaged Optics), Polymers & Interposers

• Positioning: V. The "Core Track" for Next-Generation AI Computing Power

• Core Function: CPO (Co-Packaged Optics) is the most critical technical direction for current AI computing power, co-packaging optical engines with AI chips to solve high-bandwidth interconnect issues; interposers are key to achieving high-density interconnects

◦ $SIVE: Supplier of CPO optical engines and silicon photonics chips

◦ $Aeluma(ALMU.US) Photodetector and sensor chips

◦ $POET Tech(POET.US) Photonic integration technology

◦ $Lightwave Logic(LWLG.US) R&D of polymer materials for optical communications

Layer 6: Global & Data Center Interconnect Transmission

• Positioning: VI. The "Highway" for AI Computing Power

• Core Function: High-speed optical transmission across global telecom networks between data centers, the foundation for cross-regional scheduling of AI computing power

◦ $Ciena(CIEN.US): Ciena, global leader in telecom optical networking equipment, core supplier for DCI and backbone network equipment

Layer 7: Testing & Aging

• Core Function: Testing, aging, and validation of optical chips and modules to ensure product reliability, the final checkpoint before mass production

◦ $Formfactor(FORM.US) Provider of optical test and measurement technology

◦ $Aehr Test(AEHR.US): Semiconductor/optical chip test equipment