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 r_3dB. 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 r_3dB 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 r_3dB is slightly greater than that of the V-groove structure.