Cyclic vertical cavity semiconductor laser arrays with odd numbers of elements: Lasing modes and symmetry breaking

Array modes of cyclic vertical cavity laser arrays with odd numbers of elements were explored experimentally and theoretically. The odd antiphase array mode is prohibited by the circular symmetry, and the lowest-loss modes are degenerated. Slight inhomogenities drive the array mode structure to experience spontaneous symmetry breaking, leading by means of mode degeneracy removal to stable operation characterized by an antiphase lasing mode with an even number of lobes. Circular laser arrays of 3-19 elements were measured; all were lasing in a stable even-array mode, exhibiting 2-18 intensity lobes for both the near and the far fields. (C) 1996 Optical Society of America.