Harvard University researchers have stopped light with all its photons intact for the first time by firing a short burst of red laser light into a gas of hot rubidium atoms.

This is then “frozen” with the help of two control beams. The light in the control beams interacts with the rubidium atoms to create layers that alternately transmit and reflect the pulse.

As the signal tries to propagate through these layers, the photons bounce backwards and forwards between them. As a result, the light is “frozen” in place. This could be useful for telecommunications systems that send optical signals or in quantum computers.