Longitudinal 2 x 2 Switching Configurations Based on Thermo-Optically Addressed Dielectric-Loaded Plasmonic Waveguides

Longitudinal 2 × 2 thermo-optic switches based on dielectric-loaded plasmonic circuitry are thoroughly studied using vectorial numerical tools, i.e., an eigenmode solver and a beam propagation method, implemented with the finite-element technique. The switching configurations studied are based on the Mach-Zehnder interferometer (MZI) and a novel multimode interference (MMI) design. Both components offer improved performance, with respect to comparable microring-based ones, exhibiting larger bandwidth and output port extinction ratio, allowing values up to 30 dB. The reference MZI configuration has better overall performance when compared to the MMI, mainly in terms of available bandwidth.