Enhanced performance of nonlinear optical loop mirrors using SOAs with robust transparency

Summary form only given. The transparent semiconductor optical amplifier-based nonlinear optical loop mirror (TSOA-MOLM) exhibits fast switching with a recovery time of the order of a low picoseconds, cascadable switching functionalities, low cross-talk between adjacent channels and low noise figures. The transparency carrier density of the SOA is, however, significantly dependent upon the pump pulse power, which would seriously limit the practical utilisation of TSOA-NOLMs. In this paper, it is shown that long SOAs can be employed in TSOA-NOLMs to both considerably reduce the pump power dependence of the transparency carrier density of the SOAs and also to significantly increase the transmission of the switches.