Self-consistent analysis of nonlinear multimode dynamics in external cavity laser diodes

The model presented in this paper views the system as a coupled-cavity problem, and self-consistently calculates the longitudinal modes of the cavity and the optical susceptibility in semiconductor lasers. The optical susceptibility is calculated over the full frequency range of expected optical cavity modes and includes many-body effects. In this way the evolution of the mode spectrum from spontaneous emission can be obtained. The model is applied to a specific topical phenomenon-the observation of low frequency fluctuations, and the results are compared with those of single mode models, in order to assess the importance of multi-mode effects on low frequency fluctuation (LFF) dynamics.