Lightmatter

Lightmatter develops photonic interconnect technology that moves data between AI chips using light instead of electrical signals, delivering dramatically higher bandwidth with lower power consumption than traditional copper interconnects. The Mountain View startup's Passage platform uses 3D-stacked photonic chips to solve the bandwidth bottlenecks limiting AI cluster scale. In October 2024, Lightmatter raised a $400M Series D at a $4.4B valuation led by T. Rowe Price, bringing total funding to $850M — with CEO Nicholas Harris stating it could be their last private round before an IPO.