Abstract

Conical emission is a directional, off-axial emission that might occur when a strong laser beam propagates through a dense atomic medium (e.g., Ref. 1 and the references therein). In spite of many investigations, the phenomenon still seems not to be fully understood, and various observations yield inconsistent results.^1-3 In most cases a single light cone was observed, yet in some experiments with sodium vapors more than one ring, i.e., light cone, was seen. We report on what is to our knowledge the first observation of multiple cones in barium vapor for blue and red detuning of the laser light from atomic resonance. Our experiment was performed in barium to avoid possible additional effects that might arise from fine and hyperfine structures.

© 1991 Optical Society of America