Yield analysis of non-AR-coated DFB lasers with combined index and gain coupling

Abstract

The threshold gain difference for DFB lasers with various degrees of gain coupling and different strengths of facet reflectivities is calculated as a function of the random phases between grating and facet reflectivities. From this, the yield for single mode behaviour is determined. It is shown that even for cleaved facets a relevant improvement in terms of threshold gain difference is obtained by introducing a small fraction of gain coupling.