Design of Nanoscale Hybrid Insulator-Metal-Insulator Plasmonic Waveguide

Optical properties of the fundamental hybrid mode of hybrid insulator-metal-insulator plasmonic waveguide (HIMIPW), consists of insulator-metal-insulator sandwiched between two dielectric waveguides, have been investigated to achieve the relatively high propagation length and large normalized intensity at 1.55 mu m of working wavelength. The main aim of the current work is to settle the issues of high power loss and size of waveguide dimension. The optimum waveguide dimension of 0.2 mu m x 0.02 mu m, has obtained the propagation length of similar to 289.26 mu m. The normalized intensity in the low-index region of the HIMIPW has been achieved as similar to 67.50 mu m(-2), which is due to the electric field enhancement in this region. It is beneficial for the design of applications, such as bio-sensing, optical manipulations, etc. The electric field intensity has attained the highest value at the wavelength of 1.55 mu m, for the optimum dimension of HIMIPW (i.e., w = 0.2 mu m, t(h) = 0.2 mu m, and t(l) = 0.02 mu m), which is due to the highly localized surface plasmon resonance at the metal-dielectric interfaces. The investigation of the coupling length between the two identically parallel HIMIPWs, with a separation distance, has been done. Further to improve the coupling length, a metallic strip has been inserted between them, keeping the separation distance unchanged. The higher coupling length leads to lower crosstalk between two parallel hybrid plasmonic waveguides, which can be highly useful to achieve the larger integration over the photonic chip.