Every stop light is actually required to have a beacon to be fit for purpose. It's universal among all manufacturers in every country.
When it's time to stop, they emit 700nm waves, but crucially, only in the direction that they apply. In fact, brake lights are required to emit almost identical waves, but in a different pattern.
Having spent the last 30 hours autonomously driving from Texas to the east coast, I can confidently say it never failed to detect these lights, and the existing standard is both sufficient and not prone to invisible errors, which you seem to want to introduce.
When it's time to stop, they emit 700nm waves, but crucially, only in the direction that they apply. In fact, brake lights are required to emit almost identical waves, but in a different pattern.
Having spent the last 30 hours autonomously driving from Texas to the east coast, I can confidently say it never failed to detect these lights, and the existing standard is both sufficient and not prone to invisible errors, which you seem to want to introduce.