Abstract

It was shown that the inclusion of diffraction terms into the usual Maxwell–Bloch equations lead to the appearance of "optical vortices"¹ and in the limit of small field amplitudes and large decay rates for the atomic variables, those equations are isomorphic to the Guinzburg–Landau one with constant complex parameters. However, in the case of the "longitudinal" boundary conditions for a real laser, the equations have parameters that depend on the spatial coordinates.² Here we show that the inclusion of those terms leads also to the appearance of defects, a decay in the spatial correlation function, and therefore to defect-mediated turbulence. In particular, this system does not require the conservation of the topological charge. We analyzed the motion of defects, their interaction, and their influence on the temporal dynamics. The numerical results are compared with experimental data obtained from a CO₂ laser with a large Fresnel number.

© 1990 Optical Society of America