Application of M-PML absorbing boundary conditions to the numerical simulation of wave propagation in anisotropic media. Part II: Stability

This paper deals with detailed properties of M-PML (Multiaxial Perfectly Matched Layer) absorbing boundary conditions, which are used when the computational domain is limited. These conditions are stable for any type of anisotropy with the correct choice of a stabilization parameter. In the first part of this paper, [3], the authors show that the reflectivity is a linear function of the stabilization parameter. Based on this study, the problem of finding an optimal stabilization parameter that provides stability and minimal reflection is formulated. A necessary M-PML stability condition that allows limiting the lower values of the stabilization parameter is obtained. It is shown that this criterion is not sufficient.