Bistability Analysis for Optical Flip-Flops Based on a SOA-MZI With Feedback

Theoretical models that are used to describe the stable output states in optical flip-flop configurations based on a single semiconductor-optical-amplifier-based Mach-Zehnder interferometer with feedback are derived. The calculated flip-flop states, as well as optical bistability curves, allow for an accurate characterization of the flip-flop operation during the design phase prior to experiments, showing that the system parameters must be carefully chosen to obtain correct operation. Furthermore, dynamic effects such as switching time and pulse-energy requirements are also obtained as a function of the length of the feedback loop.