Improved Trenched Channel Plasmonic Waveguide

In this paper, the modal analysis of a novel design of three trenched single mode channel plasmon polariton is introduced and analyzed using the full-vectorial finite difference method for linear oblique and curved interfaces (FVFD-LOCI). The analyzed parameters are the real effective index, propagation length, and lateral mode radius. In addition, the figure of merit (FOM) defined as the ratio between propagation length and lateral mode radius is also studied. The analysis is performed for different channel plasmon polariton (CPP) waveguides; trenched-groove, V-groove and the suggested three trenched structure over a specific spectral range (200-550 THz). The selected band of frequency is chosen to ensure the existence of the CPP fundamental mode. The reported design offers very high FOM at low frequency band (200-350 THz) compared to the well known V-groove structure. However, the lateral mode radius of the suggested three trenched structure is slightly smaller than that of the V-groove structure. For high frequency band (350-550 THz), the FOM is still higher than that of the V-groove structure while the lateral mode radius is slightly greater than that of the V-groove structure.