Regardless of what it is used for, the only similarity I can find is in the name. It shouldn't matter if Emily's mirror is personnel-usable for PAs or starship-grade, it should be considered original technology. A relatively (I'd never heard it anywhere but here and Halo) unoriginal name, of course, but the name is just what it is.
If you insist that this is "derivative technology" and has no place in the SARP, then this all becomes the sort of situation that would require computer companies to think up another name for a "motherboard" because other companies already use the term for the part, or for the players of the SARP to find another name for "bullet". The quantum mirror is a basic piece of a sensor system, it's not the complete system in and of itself. You can't make it any more simple without breaking it down into atomic elements (which Emily did already).
Besides, the Halo wiki doesn't explain what their mirror actually is, nor how it does what it does, except that it serves as a "motion sensor" (which could be nothing more than a normal motion-detector). Emily's mirror can determine much more detail, and the inner workings are, imho, well-defined enough to differentiate this from Halo-tech and be able to stand apart. The name and basic purpose (sensing) are the only connections.