Influence of the feedback phase on the delay dynamics of semiconductor lasers with short external cavities

A detailed analysis of the short external cavity regime is presented, concentrating in particular on the role of the optical feedback phase accumulated within the external cavity. Evidence for a 2π-periodic dynamical scenario under variation of the cavity phase is given. Results depict rf spectra of the intensity dynamics obtained over one cycle of the feedback phase which has been varied via slight injection current changes. A detailed characterization of the dynamical scenario is provided and the underlying mechanism is discussed by providing numerical modelling via the Lang-Kobayashi equations. Further insight can be gained by applying recently developed tools of bifurcation analysis, completing a comprehensive picture of this model system.