New description of transmission of an SOA-based sagnac loop and its application for NRZ wavelength conversion

Sagnac interferometric loops with a semiconductor optical amplifiers (SOA) have found important applications for optical signal processing and communication networks. We derive a new description of the transmission of an SOA-based Sagnac loop by including the influence of loop birefringence. Based on this new description, we theoretically analyze and experimentally demonstrate NRZ wavelength conversion using a Sagnac loop with an SOA at asymmetric position. We also show that the converted signal with an SOA-based Sagnac loop has lower pattern dependent effect and smaller power penalty compared with the converted signal using cross gain modulation effect