Analysis of the dispersion characteristics and attenuation of a semiconductor cylindrical waveguide with plasma regions

In this work, a versatile and efficient formulation involving the Finite-Difference Frequency-Domain (FDFD) method is used in the analysis of the propagation characteristics of a dielectric cylindrical waveguide of constant circular cross section along the propagation direction. Here the losses are considered. In this formulation, the FDFD method is applied in the numerical solution of the scalar wave equation, written in terms of the transverse components of the magnetic field. As a result, a conventional eigenvalue problem is obtained without the presence of spurious modes (present in previous formulations), due to the implicit inclusion of the divergence of the magnetic field equal to zero. The formulation is applied in order to obtain the dispersion characteristics and attenuation of a cylindrical waveguide, constituted of semiconductor material, with isotropic plasma regions. Plasma is generated by light incidence on semiconductor surface and then the propagation characteristics of the structure become dependent on the plasma layer dimensions. When φ = 0° a resonator is obtained.