Nonlinear beam shaping by a cloud of cold Rb atoms G. Labeyrie, T. Ackemann, B. Klappauf, M. Pesch, G. L. Lippi and R. Kaiser Eur. Phys. J. D, 22 3 (2003) 473-483 Published online: 18 February 2003 DOI: 10.1140/epjd/e2003-00046-4