Coherent has announced plans to quadruple its 6-inch indium phosphide substrate capacity, a $50 million bet that signals a structural shift in the photonics supply chain, according to Yole Group analysis.
InP is the material substrate for lasers, modulators, and photodetectors used in optical transceivers that move data inside AI data centers. As AI compute clusters scale to hundreds of thousands of accelerators, the optical interconnect layer has become a bottleneck that only InP-based components can economically solve at volume.
Yole Group analyst Lakshman Srinivasan noted that when the largest volume producer of 6-inch InP intends to quadruple capacity, the signal extends well beyond a single facility expansion. The $50 million sum is modest compared to the capital expenditures the semiconductor industry is spending, but the strategic direction is significant: InP supply has been a quietly growing concern for two years as datacom bandwidth demand outpaces substrate production.
The expansion addresses an emerging pinch point in the AI infrastructure supply chain. While most attention focuses on GPU availability and HBM memory allocation, the optical transceiver layer that connects these components into functional clusters has become an increasingly critical constraint. Coherent’s capacity move suggests the industry is beginning to address this bottleneck before it becomes a systemic limitation for AI compute expansion.
