Dynamics of a Single-Mode Semiconductor Laser with Incoherent Optical Feedback

A new model of an injection semiconductor laser with optical feedback, which generalizes the Lang–Kobayashi equations to the case of incoherent feedback, is proposed. Within the framework of this model, the above-mentioned equations are supplemented by the stochastic variable, which simulates the random phase difference between the field inside the resonator and the field returning to the laser after travelling over the feedback loop. It is shown that transition from coherent to incoherent feedback in the case of weak feedback results in the replacement of dynamic chaos by almost stationary lasing with a slightly noisy intensity. However, a much stronger incoherent feedback can lead to chaotic oscillations. The proposed model has both noise and deterministic solutions, which indicates the impossibility to develop a purely dynamical model of a semiconductor laser with incoherent optical feedback.