Direct modulation frequency response of semiconductor ring laser

This paper demonstrates the measurements of direct modulation bandwidth of a bistable racetrack semiconductor ring laser. It is exhibited using the phenomenon of optical injection-locking in the master-slave layout. Semiconductor ring laser is employed as the slave laser. Modulated signal is injected at 1530 nm, which is about 20nm away from the main lasing mode. The frequency response of the main mode is measured, thus the signal is modulated by the SRL cavity. The modulation bandwidth of the SRL is found to be 15 GHz. Furthermore, the proposed method can be recommended for monolithic integration. This scheme can provide a low-cost modulation source for future communication systems.