The Cornell team, who declined an interview pending the paper's publication, manipulated light in a fiber-optic cable using a time lens, a silicon device originally developed to speed up data transfer. Some of the light passing through this lens speeds up, and some slows down. The waves divide, Moses-style, creating a gap of darkness. A second lens farther along the cable then stitches the light back together so that it arrives at its destination intact, with no record of a hole — or anything that happened during this brief window of opportunity.15 trillionths of a second.
This hole lasted for 15 trillionths of a second, long enough to conceal pulses of light created inside the cloak
I'll be impressed when they get it to 10 trillionths - then I can do something sneaky.