Influence of interferometric cross talk in a cascade of 10-Gbit/s wavelength routers and an improved Gaussian cross talk model

Summary form only given. Integrated optical N/spl times/N wavelength routers based on arrayed-waveguide gratings (AWGs) are likely to become key devices in future WDM networks. A cascade of wavelength routers is formed when several N/spl times/N networks are interconnected. Due to the nonideal transfer function of physical AWGs, a node will receive not only the signal from the node it is connected to, but also cross talk at the same wavelength from the other nodes. In a cascade of AWG routers, the cross talk will accumulate and thereby limit the number of stages. The Gaussian cross talk model is considered to be a worst-case model when investigating multiple independent cross talk sources, but higher power penalties than predicted by this model have been found. We extend the model by including the signal extinction ratio and spontaneous emission from the optical preamplifier in our receiver. Experimentally, a recirculating loop is used for investigation of router cascades. Very good agreement is demonstrated between the measured penalty and the penalty predicted from our improved Gaussian cross talk model.