Analysis of operating characteristic of the SOA-MZI based all-optical add/drop multiplexer

摘要

The operating characteristic of the semiconductor optical amplifier based Mach-Zehnder interferometer (SOA-MZI) all-optical add/drop multiplexier (AO-ADM) for optical time division multiplexing (OTDM) networks is analyzed in this paper. Based on the analysis of the crosstalk, the π and -π demultiplexing point operation are analyzed and compared. We find that, for the traditional symmetrical operation mode of the SOA-MZI, -π demultiplexing point operation is favorable to have relative good extinction ratios for two output ports simultaneously. However the extinction ratio of the dropped and transmitted channels are still very limited arising from the gain dynamics of SOA and the symmetrical configuration of MZI employed. Besides, Studies show that there is a large amplitude modulation (AM) in the transmitted channel originating from the gain dynamics of the SOA. To tackle these problems, the asymmetrical operation mode is proposed. Analysis shows the asymmetrical operation mode can improve the extinction ratios of the dropped and transmitted channels by optimizing the splitting ratio and the relative small signal gain ratio of the two SOAs. The AM of the transmitted channel for the asymmetrical operation is also less than that of the transmitted channel for the symmetrical operation mode.