Dynamics of the square optical vortex lattice in the model of broad-area laser

Dynamics of the square optical vortex lattice in broad-area lasers is investigated both numerically and analytically on a base of the full system of Maxwell-Bloch equations. A linear analysis and numerical simulations show the formation of the stationary vortex lattice near the laser threshold. The pump parameter increasing results in the Andronov-Hopf bifurcation and the emergence of vortex lattice oscillations. At further increase of pump parameter, the lattice is destroyed and non-regular moving of separated vortices is observed. Bifurcation diagrams are obtained.