Channel Bragg-plasmon coupled waveguide

Abstract

We present a detailed analysis and recipe for designing a channel Bragg-plasmon coupled waveguide where the intermodal coupling between a bandgap-guided mode and surface plasmon mode substantially modifies the phase-velocity dispersion slope of supermodes. This leads to appreciably large group-velocity-dispersion with peak value of ≈4.33x104 ps/km-nm close to the optical communication band as well as interaction bandwidth of about 765 pm for 1 cm long waveguide. We also found that bandgap guided Bragg modes exhibit stronger dispersive features than the plasmon modes around ~ 1.50 μm which is exactly opposite to what is usually observed in visible region. The impact of waveguide parameters such as channel width etc. on mode-coupling mechanism is also studied with significant emphasis on the propagation loss suffered by the supermodes of the structure.