Cloaking idea traps a rainbow

Researchers have trapped a rainbow – slowing light to a near-stop – in an array of 25,000 “invisibility cloaks”, each smaller than a hair’s breadth.

We shall leave aside for the moment the fact that their definition of “near-stop” is not the same as mine, consisting as it seems to of separating the light into its constituent colours.

In essence, they have arranged some tiny lenses in an array, creating a tiny cloaked area in the centre.  You can’t see what’s there, because the light is bent around it by the lenses. The rainbow effect comes from slowing some of the light more than the rest.

If we can slow light down, does this mean that FTL travel is easier than we thought?  It wouldn’t help us actually get anywhere faster, but if we slow light down enough, we could go faster than it.