Optical Kerr Nonlinear Performance of Metal-Cap Wedged-Shape Hybrid Plasmonic Waveguide

This paper aims to investigate the enhancement of Kerr nonlinear performance caused by more optical confinement and longer propagation length due to different metal-cap wedge-shaped hybrid plasmonic waveguide geometric parameters. In this work, we will focus on Kerr nonlinear effect, and analyze how the different waveguide geometries can enhance this effect. Our theoretical investigation shows that the presented nonlinear wedge-shaped hybrid plasmonic waveguide structure with a wedge-shaped gap is suitable for photonic integrated circuits based on the hybrid plasmonic passive waveguide, and is a suitable candidate for the photonic devices at nano-scales with nonlinearity. It is also found that the investigated structure can have a longer propagation length of 2120 μm at a 10 nm thick nonlinear dielectric. The minimum effective mode area of the investigated structure is 0.0263 μm2 and the maximum nonlinear coefficient is 𝛾=3.5 ×10^6W−1Km−1. Also, the confinement factor of the DDMEBT layer is calculated by changing the wedge angle α. It is found that the surface mode has a maximum confinement factor of 0.33 when α=35°. The modal and nonlinear properties of the hybrid plasmonic waveguides were analytically determined as well by using the finite element method (FEM). Simulation results show that the wedge-shaped hybrid plasmonic waveguide provides good performance for nonlinear applications such as optical switching at the optical wavelength of 𝜆 1550 nmnm.