Self-pulsating semiconductor lasers for high bit-rate all-optical clock recovery
Résumé
Clock recovery using self pulsating semiconductor laser structure is a sophisticated signal processing inside the device, involving optical injection locking, gain and index modulation, self pulsation, radiofrequency oscillation synchronization, and phase noise filtering. The mutual injection of the longitudinal mode and the passive mode locking leading to self pulsation is analyzed by using multimode rate equations. Self pulsation is easily achievable and is characterized by a large reduction of the RF spectral line width, as compared to those of the optical modes involved in the beating process. When they are injected by a power modulated optical signal, the self pulsating laser structures act as all-optical clock recovery devices. The self pulsation line width is found to be determinant to fulfill the high bit-rate optical communications and optical signal processing clock recovery property requirement.