Yes, exactly, I came to the same realisation that was an appropriate label and made an edit to describe it as such. In fact comparing it to FIFO as you have mak

Yes, exactly, I came to the same realisation that was an appropriate label and made an edit to describe it as such. In fact comparing it to FIFO as you have makes even more sense so I've edited it again. Surface reflections are FIFO, because there is no medium, no "storage"; This novel medium based reflection is LIFO, based upon whatever is traversing the medium at the time of the change to the medium. It's not magic, but it's an interesting way to achieve this in pure photonics, without first converting to something more manageable like electronics... it also doesn't require discrete memory like electronics, it's kind of analogue processing but with a buffer? but can only support analogue processing.