Generation of chaos in semiconductor ring laser with optical injection

The unidirectional master-slave scheme for generating chaos is demonstrated, which consists of a distributed feedback laser and a semiconductor ring laser(SRL). The SRL, under suitable bias current, has a chaotic output due to an optical injection from the master laser with suitable detuning frequency and injection coefficient. By numerical simulation based on the rate equations of the semiconductor ring laser subjected to an external injection, bifurcation diagrams are derived, of the parameters of interest: the detuning frequency, injection coefficient and the bias current of the SRL. The result shows that, high-quality chaos with flat power spectrum can be generated in the SRL when the detuning frequency is 3.9 GHz, the injection coefficient is 0.07 and the bias current of the SRL is 81 mA.