A laser can be within spec. A scanner can be within spec. The optical calibration and the product motion can each be exactly where they should be, and the result on the part can still miss. Not because any single component failed, but because nothing was synchronizing them around the same instant. That's the problem we're solving. Photon Interlock is the architecture we're building and testing to solve it: a control layer designed to lock laser timing, scanner phase, optical calibration, and product motion to a single reference: the individual pulse. One pulse, one instant, one exact position. That's the target we're validating against.

Why timing becomes positioning
At production speeds, a timing error isn't a delay: it's a location error. At 250 m/s, a 20-nanosecond lag translates directly into roughly 5 micrometers of positional error on the part. Below a certain speed, timing and position can be treated as separate problems. Above it, they're the same problem, and that's a matter of physics, not implementation. Most systems tune components in isolation and hope the assembly adds up. Our approach starts from the opposite direction: define the system-level synchronization first, then let component selection follow from what the application actually needs.

The mechanical foundation: resonant scanning
Underneath Photon Interlock sits a flexure-based scanning mirror, driven at its mechanical resonance by a magnet-and-coil actuator, at a single fixed frequency. Bidirectional scanning is the efficient default: the mirror does useful work on both the forward and return stroke. Because resonance is a fixed physical property of the mechanism rather than a tunable software parameter, it gives us a stable, repeatable reference to synchronize everything else against: the foundation the rest of the architecture is built on.