The onset of coherence collapse in DFB lasers

How the onset of coherence collapse in distributed-feedback (DFB) lasers varies with the laser output power has been measured. Theory predicts that as a laser's output power is increased, the amount of back-reflected light necessary to cause coherence collapse should also increase, yet two of the four lasers studied become dramatically more sensitive to back reflections at higher output powers. It is speculated that changes in the carrier density in these lasers cause this device-dependent behavior.<
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