Oriented perfectly matched layer with flexible parameters for waveguide discontinuity problems

A new arbitrarily oriented perfectly matched layer (PML) is developed for truncating finite element meshes in waveguiding problems. The PML can have any orientation with flexible parameters such as stretching variables and thicknesses. It is based on the PMLs stretched step-by-step along each normal direction of their surface. The formulation is easily adapted within the finite element method frameworks, providing good simulation results.