Extraction of optimized parameters for Si0.6Ge0.4 material and SPP mode propagation through Si0.6Ge0.4/Ag/Si0.6Ge0.4 waveguide

The Lorentz model and modified Debye model (MDM) parameters for Si_0.6Ge_0.4 are presented. A nonlinear optimization algorithm is developed. The obtained parameters are used to determine the complex relative permittivity of Si_0.6Ge_0.4, and compared with the experimental data for validation. Finally the obtained parameters are used to analyze the properties of symmetric surface plasmon polariton (SPP) mode propagation in a dielectric-metal-dielectric (DMD) material constructed with silver (Ag) and Si_0.6Ge_0.4 for further verifying the extracted parameters.