A Novel All-Optical Flip-Flop Based on Single-Wavelength SOA-MZI

In this paper, a novel set-reset all-optical flip-flop (SR-AOFF) is proposed. The SR-AOFF is based on semiconductor optical amplifier-Mach Zehnder Interferometer (SOA-MZI) operating at a single wavelength. It is composed of two coupled SOA-MZIs using a common bidirectional coupler. Due to self phase modulation (SPM) and self gain modulation (SGM) in SOAs, two SOA-MZI switches modulate the injected photon rate of each other. This process occurs in a positive feedback loop to demonstrate an optical bistabilty. The simulation results show that excitation pulses with 35ps duration and optical energy of 7.5fJ can switch the output states. Switching transition time is about 110ps and is equal for leading and falling edges. The output power of this flip-flop is estimated to be in the order of 20 milliWatts.