Aehr Test Systems has a proven lead in a test step AI optics needs but few can run at scale: high-power wafer-level burn-in for silicon photonics. Co-packaged optics makes it mandatory, since a chip failing after bonding scraps the whole switch, and newer devices need 2-4x more burn-in power. Bookings hit $37.2M, up over 500% in a quarter, at a book-to-bill above 3.5x. Goldman sees optical networking growing from about $15B in 2026 to $154B by 2028, and the test bottleneck forms first. x.com