On the performance of advanced integrated microring filters for switching applications in next-generation elastic optical networks

We investigate the use of integrated advanced microring resonator-based sum-difference all-pass optical filters for switching applications in circuit-switched elastic optical networks. A practical design taking into account optical losses accordingly to typical reported values for strip waveguides in silicon-on-insulator technology is considered. By incorporating tuning elements (i.e., standard phase shifters), three different synthetized elliptic filters are emulated in the same physical structure showing the potential in terms of bandwidth configurability of the architecture. Practical filter design rules for standard silicon-on-insulator single-mode strip waveguides are also discussed. Beside possible advantages in terms of reduced fabrication costs, simulations performed on Nyquist PM-QPSK signals with different channel capacities over 50, 37.5 and 25 GHz frequency slots suggest that the proposed structure can achieve similar or better performance than commercial spectrum selective switch filters.