NEGATIVE DIFFERENTIAL COUPLING IN COMPLEX-COUPLED DISTRIBUTED-FEEDBACK SEMICONDUCTOR-LASERS - A LONGITUDINAL ANALYSIS

A complex-coupled distributed feedback laser using a novel mechanism f or creating a periodic gain is investigated. A one-dimensional longitu dinal analysis is developed to predict the change in the coupling stre ngth when the carrier density is perturbed. Earlier reports have shown that this differential coupling affects the linewidth, with negative differential coupling offering the possibility for the most significan t reductions in the linewidth enhancement factor. The analysis predict s that the linewidth enhancement factor can be reduced by about a fact or of 2 because of the negative differential coupling for the particul ar design studied. (C) 1996 American Institute of Physics.