In 1999, Lene Hau built a machine that slowed traveling light down to a mere 38 mph using a new form of matter. Hau's team created a Bose-Einstein condensate with sodium atoms that were laser cooled within billionths of absolute zero in order to take advantage of light impeding processes. Refining their procedure, Hau's team was able to further slow light down to only a single mile per hour in 2000. Still using the BEC, physicists developed a technique for 'storing' a light pattern by slowing the beam and using lasers to encode the light's properties onto atoms. When they desired to recreate the beam, they reverse the process to re-instate the light's properties and accelerate it back to light speed.

Five years later, scientists have developed semiconductor films that impede light's travel to ¹/₄₀th the original speed at room temperature. While the new technique is not nearly as effective as the BEC medium, researchers believe continued study will result in the ability to completely stop a beam of light. Applications of such technology may allow for direct manipulation of the light lending itself for optical computing or quantum computers.