Author Affiliations

L. Hollberg,^a,* A.S. Zibrov,^a,b,c H.G. Robinson,^a M.D. Lukin,^b,d D.E. Nikonov,^b,d M.O. Scully,^b,d E. Arimondo,^e and V.L. Veliehansky^e

^aNational Institute of Standards and Technology, 325 Broadway, Boulder, CO 80303, tel 303-497-5770, fax 303-497-7845

^bTexas A&M University, College Station, TX 77843

^cLebedev Institute of Physics, Moscow, 117924 Russia

^dMax-Planck-lnstitut für Quantenoptik, D-85748, Garching, Germany

^eDipartimento di Fisica, Universita di Pisa, Pisa, Italy

^*Corresponding author: hollberg@boulder.nist.gov