Extinction ratio improvement by an all-optical signal regenerator with a semiconductor optical amplifier and a Sagnac loop

In this paper, we present the operation of an all-optical signal regenerator (AOSR). The AOSR is based on a semiconductor optical amplifier (SOA), which is incorporated in an asymmetric Sagnac loop (ASL). We show experimentally that the AOSR is capable of improving the input signal extinction ratio (ER) considerably. We present a theoretical model, which explains this improvement, and we illustrate a qualitatively similar behavior with a simulation.