Enhancing the PML absorbing boundary conditions for the wave equation

The dynamics of wave propagation and interactions in general media is described either by the system of Maxwell´s equations, or by the wave equation. This paper focuses on problems modeled by the scalar wave equation, with one or more boundaries at infinity. The computational domain is truncated by a perfectly matched layer (PML) absorbing boundary condition (ABC) modified specifically for wave-equation applications. A problem independent approach is used to enhance the PML performance within the whole frequency band of excitation, in the presence of both evanescent and propagating fields. Numerical reflections below 0.1% are achieved with PML thickness of only six to eight cells, in both open and guided-wave problems.