Abstract: We proposed an uniaxial optimal perfectly matched layer (PML) method for solving timedomain acoustic scattering problem based on the Laplace transform and the complex coordinate stretching in the frequency domain. The uniaxial optimal PML was constructed by this method in a rectangular domain, which provided a flexible and effictive calculation method for the scattering problems of anisotropic scatters. A small parameter ε₀ was introduced into the absorption function, so that the calculation of the optimal PML method for scattering problem was no longer dependent on the thickness of the PML layer δ. The results show that the optimal PML solution converges exponentially to the solution of the original scattering problem if the parameter ε₀ is sufficiently small.

Key words: optimal PML method, exponential convergence, timedomain scattering