Instabilities in semiconductor laser with optical feedback and modulation

A recent investigation into the operation of a semiconductor laser with optical feedback and direct current modulation has revealed in detail the different dynamical states displayed by the system. The dynamics are driven by the main frequencies in the system; the external cavity frequency, the injection current modulation frequency and relaxation oscillation frequency. Varying optical feedback level, as well as the power and frequency of the injection current modulation resulted in the laser system displaying a variety of dynamics ranging from stable, periodic signals to unstable, chaotic outputs.