FREQUENCY LOCKING OF SUPERMODES AND STABILITY OF THE OUT-OF-PHASE-LOCKED STATE IN ONE-DIMENSIONAL AND 2-DIMENSIONAL ARRAYS OF VERTICAL-CAVITY SURFACE-EMITTING LASERS

In large arrays with equally pumped lasers the out-of-phase-locked sta te is a combination of several supermodes of the array that are locked to a common frequency. The far-field pattern is four lobed because th e out-of-phase supermode is largely dominant. An approximated analytic al expression for the locking threshold is found, and saturable disper sion is indicated as the physical mechanism that selects the out-of-ph ase-locked state. (C) 1997 Optical Society of America.