On the design of semiconductor optical amplifier-assisted Sagnac interferometer with full data dual output switching capability

The ability of a semiconductor optical amplifier assisted Sagnac interferometer to support error-free as well as pattern-independent operation at both of its output ports simultaneously when all of the incoming data can potentially be switched to them is investigated and demonstrated. For this purpose a numerical model is used to simulate the operation of the considered module so as to identify under which working conditions this full data dual output switching mode is possible. The thorough analysis and interpretation of the results obtained from the evaluation of the impact that each critical parameter has on the defined performance metrics allows to infer that meeting at the limit the criterion for the Q-factor at both outputs is determined by the transmission port for all of them but the carrier lifetime, for which the reflection port prevails. However this is not enough to guarantee that the pseudo-eye diagrams acquire their desired form because, although the amplitude modulation is adequate for both cases, the extinction ratio is low. Instead, the achievement of both logically correct and high quality switching demands further refinement of the specified minimum requirements and the selection of the key parameters in such way that the Q-factor at the reflection port is optimized. The design rules derived from this procedure can be useful for enabling the implementation of complex all-optical circuits and subsystems that exploit the specific SOA-based interferometric structure as the core building element.