On March 2, 2026, I saw NVIDIA put $2 billion into each of Lumentum and Coherent—the two big makers of the high‑power lasers external‑light‑source architectures need, per SEC filings. Coherent’s side also bundles a multibillion, multi‑year CPO supply pact through decade’s end, its CEO calling it an expansion of a more‑than‑20‑year relationship. Lumentum’s cash funds a fifth InP laser fab in North Carolina, and the billion‑dollar spend signals how seriously the chip designer takes the optical transition and how scarce it expects those lasers to be.