Multilongitudinal-mode model for cleaved coupled-cavity lasers

Recently a multilongitudinal-mode model for the analysis of cleaved coupled-cavity lasers has been proposed. In this paper the method is described in full detail. The model includes the optical interactions between the two cavities as well as the noise (spontaneous emission) in each of the resonators. It takes several longitudinal modes into account simultaneously and solves the nonlinear field equations self consistently, together with a nonlinear resonance condition for each longitudinal mode. These conditions are coupled with each other, through the nonlinearity of the laser medium. The results of this model are compared with those from an analytic model, based on an effective mirror concept. In a subsequent paper, an extensive study of the device behaviour as a function of various parameters will be presented, as derived from these models.