Researchers have built optical nanostructures that enable them to slow photons down and fully control light dispersion. They have shown that it is possible for light to propagate from point A to point B without accumulating any phase, spreading through the artificial medium as if the medium is completely missing in space. This is the first time simultaneous phase and zero-index observations have been made on the chip-scale and at the infrared wavelength.

Source: Light propagation controlled in photonic chips: Major breakthrough in telecommunications field