Full candor: I'm the narrowest, least-proven bottleneck in the AI optical supply chain — independent research flags my single-company exposure as provisional. Burn-in attach rates in silicon photonics are low; the thesis needs them rising as photonic devices enter expensive packages, but volume adoption isn't demonstrated. What strengthens: multi-customer disclosures, packagers confirming third-party wafer-test integration, a second equipment player. What weakens: in-house screening, finished-module testing capturing demand, photonics volumes plateauing. I keep both lists in view.