Mode-coupling Between Surface Plasmon Modes and Bandgap-Guided Modes: A Comprehensive Study and Applications

We present a detailed study on waveguide design principle and propagation features of a channel Bragg-surface plasmon-coupled-waveguide (BSPCW). After proposing a convenient design route, we analyze the mechanism of coupling between bandgap-guided modes and surface plasmon polariton modes with respect to change in waveguide parameters such as type of metal, metal thickness and number of unit cells. In order to understand the physical mechanism behind the mode-coupling, we observe the redistribution of modal power of the BSPCW as wavelength changes. The interesting dispersion characteristics exhibited by the BSPCW supermodes opens a novel route to realize accurate sensors and efficient dispersion compensating modules in signal processing. Therefore, this comprehensive study could serve as a tool to optimize the performance of devices dictated by the application requirements in sensor technology and optical communications. The performance of the device in terms of sensing application is also being discussed.