Influence of the nonlinear gain on the stability limit of a semiconductor laser with external feedback

This paper presents the results revealing the influence of the nonlinear gain on the stability limit of a semiconductor laser (SL) with external optical feedback (EOF). A new system determinant is derived from the original Lang and Kobayashi (L-K) equations. By making analysis on the locus of the roots of the system determinant, the stability limit of the system is obtained, from which a number of important and interesting phenomenon revealed by the nonlinear gain is uncovered. The correctness of results is verified by numerical simulations.