Comparison of different DFB laser models within the European COST 240 collaboration

The European Community COST 240 Project compares the results of different laser models obtained for static, dynamic and noise related characteristics. The devices that have been analyzed include AR-coated λ/4-shifted DFB lasers with different normalized coupling constant κL, but also DFB lasers with cleaved facets. From the numerical results obtained so far, it seems that an excellent agreement can be obtained in most cases. Also, those cases where a disagreement between models is found show where more crude approximations fail, and so can give an indication of the validity range of several approximations. A few such cases are reported in the text. Eleven laser models are compared. All of these models make use of a similar approach (allowing a nonuniform carrier density) for the static analysis, but the details of the calculations differ significantly for what concerns the dynamic and noise related characteristics.