Physicists Trap Photons and Count Them One by One

摘要

Like a photograph on the printed page, light examined on the finest scale dissolves into grains--little bundles called photons. Although physicists have pictured light in that way for some 90 years, the experimental evidence for photons has generalfybeen indirect or frustratingly nonintuitive. Physicists longed to actually see the discrete nature of light--"to count photons in a box, like marbles," as Serge Haroche of the Ecole Normale Supeneure (ENS) in Paris puts it. Now they can, in data from anexperiment by Haroche and his colleagues.