Stable states in surface-emitting semiconductor lasers

Abstract

We consider a vertical cavity surface-emitting semiconductor laser which operates with two frequency-degenerate doughnut modes, and combinations thereof. We identify a small region in the parameter space, where there is bistability between the two doughnut states, and another domain in which the TEM10 mode, and all the configurations obtained from it by rotation around the laser axis, are stable. The degeneracy by rotation can be eliminated by considering a pump region of square section; in this case there is bistability between two stationary states, in which the two intensity peaks are located along the diagonals of the square. In all the rest of the parameter space the system exhibits dynamical oscillations.