MACARTHUR RECIPIENT: LENE HAU Lene Hau, a Harvard-based optical physicist, is one of 23 recipients of a 2001 MacArthur Foundation Fellowship. Building on recent advances in atomic and condensed matter physics, Hau has shown how it is possible under precise experimental control to extend tremendously the time it takes for photons to pass through certain materials. Her latest experiments demonstrate that it is even possible to stop light completely then release it later. The $500,000, five-year grant comes with no strings attached to allow recipients to pursue their work unencumbered.