Applications of advanced microring filters for switching in next generation elastic optical networks

We investigate the use of high-order sum-difference all-pass microring 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. Simulations performed on 30 Gbaud Nyquist PM-QPSK signals show that the proposed structure can achieve similar or better performance than commercial spectrum selective switch filters. Induced OSNR penalty per node due to filtering can be reduced with the adoption of these filters, thus increasing the maximum number of nodes that can be traversed before signal is corrupted. Filters programmability in terms of bandwidth is also investigated.