Design tool and its experimental validation for SOA-based photonic signal processing

This paper reports a unified, accurate and fast simulation tool, able to describe photonic SOA-based digital processing schemes. The model exploits cross gain modulation in SOAs in time resolved analysis in which each amplifier can be thought of as a point amplifier. Simulation and experimental comparisons of the steady state and dynamic amplified spontaneous emission noise behaviour of SOA are carried out. Details of multistage modelling useful for long nonlinear SOA has been described. Implementation of schemes such as combinatorial logic functions may require many cascading SOAs and contribution of ASE noise from each amplifier also been taken into account. A procedure of the extraction of parameters from the commercial SOA utilised in the experiment is laid down. Various sources of degradation have been identified and the method for evaluation of bit error rate for complex SOA based combinatorial network has been outlined. The tool is validated through the implementation of a photonic bit comparator. Important design guidelines are extracted by the proposed tool.