Lost in transmission

A pioneering paper published in Nature last year described a 'temporal cloak' that made an isolated event undetectable by creating a temporal gap in an optical signal processing system. Now that concept has been developed further to produce a system that can hide a continuous stream of events at telecommunications data rates. Andrew Weiner and colleagues create a series of 'holes in time' by exploiting a time analogue of the self-imaging Talbot effect in optics, in which a plane wave incident on a diffraction grating produces repeated images of the grating at regular distances. Using standard optical communications components, the authors show that nearly half of the time axis can be concealed, and conceal pseudorandom digital data at rates that could potentially cloak real-world messages in secure applications.