Theoretical and experimental study of fundamental differences in the noise suppression of high-speed SOA-based all-optical switches.

We identify a fundamental difference between the ASE noise filtering properties of different all-optical SOA-based switch configurations, and divide the switches into two classes. An in-band ASE suppression ratio quantifying the difference is derived theoretically and the impact of the ASE filtering on the optical spectrum is verified experimentally using a hybrid DISC setup. ASE power suppression of around 3 dB over the total signal bandwidth is demonstrated.