Polychromatic coupled cavity model of passive structures

The authors have developed a polychromatic coupled cavity model for passive optical structures to investigate the underlying 'cold-cavity' mode spectrum of active devices, such as semiconductor lasers. The model is validated using a simple Fabry-Perot test structure and then used to study how the mode spectrum of a semiconductor laser subject to external optical feedback is affected by variations in the optical properties of the configuration (in the 'cold-cavity' limit). Significant differences in behaviour are observed in the short and long cavity limits, indicating the potentially important role the mode spectrum has in determining the dynamics of such configurations.