50 PICOSECONDS. “The gap achieved by Fridman and his colleagues was extremely small—just 50 picoseconds, or 50 trillionths of a second, in duration. The researchers note that it is possible to extend the gap somewhat, but that scattering and dispersion effects limit the scope of the temporal cloak to a few nanoseconds.”
https://lnkd.in/e-T4EeU