Lasing Mechanism Analysis of Self-Pulsating Distributed Feedback Laser Diodes and Successful Demonstration of All-Optical Signal Recovery at 40 Gbps

Three-electrode-type self-pulsating (SP) distributed feedback (DFB) laser diodes (LDs), which can recover an optical clock pulse sequence by injecting external signals, were investigated. Numerical simulations revealed that the matching relations of a round-trip phase between the two DFB sections determined the dominant lasing modes. The phase tuning section length was also confirmed by simulations to be a sensitive device parameter for pulsating frequency because of the change of the round-trip phase. We fabricated SP-DFB LDs with different phase tuning section lengths and investigated SP characteristics experimentally. A good agreement was obtained between simulations and measurements. Finally, all-optical wavelength conversion of 40 Gbps return to zero pseudo random binary sequence optical signals with timing jitter reduction was successfully demonstrated by a hybrid combination of an SP-LD and a monolithically integrated semiconductor-optical-amplifier-based Mach–Zehnder interferometer.