Effect of spatial hole burning on injection-locked vertical-cavity surface-emitting laser arrays

Injection locking of vertical-cavity surface-emitting laser arrays is analyzed at steady state, including the effect of spatial hole burning. A free-running laser array (i.e., without injection), that operates well-above threshold, can exhibit multimode oscillations. Consequently, each of the free-running modes (at different frequencies) needs a different locking injection power. For low pump levels, just above threshold, the array is single mode and, as expected, the results bear a close resemblance to those of the average gain analysis, which ignores spatial hole burning.