By Peter Weiss
In experiments over the past 2 years, physicists have been slowing laser light to a crawl, sometimes even stopping it cold within certain frigid gasses and solids.
Now, researchers at the University of Rochester (N.Y.) have dramatically slowed light within a solid at room temperature–conditions considered vital for slow light to be harnessed for practical uses such as in optical-communication systems.
By firing a specially tuned green laser through a crimson, cigarette-size rod of artificial ruby, Rochester’s Robert W. Boyd and his colleagues have decelerated light pulses to the 57-meter-per-second clip of an express train.