Self-trapping of Necklace beams in Self-focusing Kerr media
  We show that an azimuthally-periodically-modulated bright ring "necklace" beam can self-trap in self-focusing Kerr media and can exhibit stable propagation for very large distances. These are the first bright (2+1) D beams to exhibit stable self-trapping in a system described by the cubic (2+1) D Nonlinear Schrodinger Equation (NLSE). 
Marin Soljacic, Suzanne Sears, and Mordechai Segev (Princeton   University)