The steady-state propagation of spatially nonuniform σ<sup>+</sup> and σ<sup>−</sup> beams coupled by means of a homogeneously broadened <i>J</i> = ½ ↔ <i>J</i> = ½ transition is shown to give rise in many cases to a spatial separation of the beams. The nature of the nonlinear couping, which allows the response of one beam to be strongly affected by the presence of the other, and which is the root cause of the phenomenon, is examined in detail. Results for propagation both on and off resonance, with varying initial spatial configurations, demonstrate that the phenomenon of self-induced spatial separation of the copropagating components persists over a wide range of situations. A physical explanation is given in terms of an encoding/diffraction sequence, and the experimental implications are discussed.
© 1990 Optical Society of America
A. W. McCord and R. J. Ballagh, "Mutual beam reshaping by two interacting radiation modes," J. Opt. Soc. Am. B 7, 73-83 (1990)