Nonstationary vortex lattices in large-aperture class B lasers

Large-aperture class A lasers emit stationary patterns (square vortex lattices) close to the laser threshold. We show that in class B lasers the emitted patterns are in general nonstationary. The nonstationarity of the vortex lattices is related to the self-induced motion of class B laser vortices. The vortices can oscillate, can remaining spatially separated, or can annihilate and nucleate periodically, depending on the parameters of the class B laser. In the regime of chaotic motion of the vortices, class B lasers display low-dimensional deterministic chaos of transverse modes, unlike class A lasers, for which the turbulence is of the hydrodynamic type.