Crosstalk Minimization in Microring-Based Wavelength Routing Matrices

Optical switching fabrics (OSF) are gaining interest because they promise to satisfy the higher information densities demanded by each successive generation of high-end routers and switches. Silicon microring resonators (MRR) can be employed to perform switching operations directly in the optical domain. However, similarly to other devices used to build all-optical switching fabrics, such as Arrayed Waveguide Gratings (AWG), MRR-based switching fabrics might show a limited scalability in terms of port count due to the crosstalk accumulation caused by the spatial wavelengths reuse. We consider an OSF built on a Wavelength-Routing-Matrix (WRM) based on MRRs, we highlight its scalability issues and we propose a new design as well as two different strategies to limit the wavelength spatial reuse.