Confusing?

Welcome to my brain.

The speed of light (c) is generally understood to be the speed of light as it travels through a vacuum. This is considered to be 299,792,458 m/s.

However (so far) even the vacuum of space is not a "true" vacuum. Even a space vacuum, the closest we can get to a "true vacuum" in nature, may contain an equivalent of just a few hydrogen atoms per cubic meter on average in intergalactic space and these atoms will interact with light causing it to slow down.

Light itself also has unique properties due to existing as both a particle and a wave. This means that by reshaping it or having it pass through other mediums (such as water) we can cause the speed of light to actually decrease.

It strikes me that if we can produce a continuous "wave" of light in the shape of an elongated torus, we could create a tunnel (of sorts) that would act as a barrier preventing anything from being able to get to its "core". Effectively creating a "pipe" of light.

If you take this "pipe" and can make it operate continuously, then at its core you should have a more "pure vacuum" than compared to what we see with space.

If you were to then send a light beam through this "pure vacuum", it should then theoretically be possible for it to travel at a speed faster than a regular space vacuum since there would be nothing to impede its speed like a regular vacuum would.

Just a random thought.