If I am not mistaken, this is done by modulation in Fourier space. We have already been using this in optical setups for ages - at the speed of light. The inte

If I am not mistaken, this is done by modulation in Fourier space. We have already been using this in optical setups for ages - at the speed of light. The interesting part imo is the implementation of this idea in their work and the efficiency and physical size.