Physical Review A
Self-induced planar and cylindrical splitting of a laser beam in sodium vapor
A. Gahl, J. P. Seipenbusch, Andreas Aumann, M. Möller, Wulfhard K. Lange
Abstract
An almost linearly polarized laser beam focused into a sodium vapor cell may split into different patterns ranging from two spots to a spot and a ring of opposite circular polarization. The patterns are controlled by static magnetic fields of the order of the earth's field. The behavior is explained, allowing for a longitudinal component of the dielectric polarization in the paraxial wave equation. Numerical results reveal the delicate balance between light shift, influence of the magnetic field, and the creation of ground-state orientation by the competing polarization components.