Size limitations and gain optimization in semiconductor-optical-amplifier-based optical space switches

The cascadability of Semiconductor optical amplifier (SOA) gates and the size limitations for several kinds of switch architectures based on SOA's are studied theoretically. The analysis shows that the sizes of matrix-vector switches are severely limited owing to the splitting losses, waveguide losses and coupling losses. However for distributed gain matrix-vector switch and Benes switch, the accumulation of amplified spontaneous emission (ASE) noise and non-ideal extinction ratio also greatly influence the maximal sizes of switches. The calculation results also reveal that the gain optimum strategy for switches based on SOA's, which derived from steady state analysis, will not be optimum when non-ideal extinction ratio and dynamical gain saturation is considered