Lightmatter
Lightmatter sells photonic interconnects (Passage) and laser light engines (Guide) that link chips in AI data centers, to hyperscalers and AI infrastructure builders.
Lightmatter makes silicon-photonics products: the Passage 3D-stacked photonic interconnect, co-packaged optics, and Guide light engines. These move data between processors at high bandwidth and with better energy efficiency. It sells to cloud hyperscalers and AI infrastructure providers and joined the NVIDIA NVLink Fusion ecosystem in 2026. It has raised about $850M in total, including a $400M Series D led by T. Rowe Price in October 2024 at a $4.4B valuation. Third-party estimates put 2023 revenue at about $50M. Sources disagree on where it is headquartered, with its own site listing Mountain View and some databases listing Boston.
