I did interpret it as effectively reflecting along the same path, I was using "buffer" in a more abstract sense to compare how it would be processed digitally.

I did interpret it as effectively reflecting along the same path, I was using "buffer" in a more abstract sense to compare how it would be processed digitally. But I don't doubt I've misunderstood something, my description of photons traversing the medium is probably what sounds physically inaccurate, I'm no expert in photonics and don't really know what a PCM is. As someone who does, are you able to corroborate whether the effect differs abstractly from what I described in terms of reversing the signal, as in a LIFO? Because this was my gripe with the article, the way the concept was explained makes it sounds like something more than it is.