Modelling effects of degradation on spectral stability of distributed feedback lasers

Modelling is used to simulate the effects of degradation on the drive current and spectral characteristics of DFB lasers. As an example, calculations are presented of the effects on uniform grating and λ/4 phase shift DFB lasers of changes made in localised injected current density and in lifetime of carriers for linear non-radiative recombination. The aim of the work is to evaluate modelling as a technique for comparing the susceptibility of different laser designs to spectral instability, with a view to selecting designs of the greatest stability.