Automatic design of NxN integrated Beneš optical switch

We propose a general procedure for the automatic design of N x N integrated optical switches using the Beneš configuration based on ring filters, suitable for multi-hop routing in meshed optical networks. The basic switch components (waveguides, couplers, optical crossings) are selected from the process development kit (PDK) of the target platform, and can be integrated with user-defined custom components. The described procedure is able to automatically select the optimal number of rings and their proper routing, minimizing the number of optical crossings and reducing the system transmission losses. The generated topology can be directly simulated in the Synopsys OptSim© environment at a system level. There, the impact of the design options on transmission performances is evaluated for the chosen signal modulation scheme and numerical simulations are automatically executed to determine, among the 2^M possible optical paths across the electrically tuned M rings, the only N! configurations required to generate all the permutations of the inputs signals to the output ports minimizing the transmission BER. Finally, the generated Beneš switch can be converted to a GDSII mask targeting the foundry of choice and manual adjustment to the layout can be made. The automatic procedure takes advantage of the vertical integration of the Synopsys environment, which allows to perform a comprehensive investigation of the whole photonic device, from the component design to the system level analysis, thanks to the integration of Optsim- optical communication system, Optsim schematic-driven photonic circuit, Rsoft component design tools, and OptoDesigner© mask layout.