An Improved New Implementation of Complex Frequency Shifted PML for the FDTD Method

A new implementation of the perfectly matched layer absorbing boundary for finite-difference time-domain grids is presented. The approach which is based on the complex co-ordinate stretching perfectly matched layer (PML) formulation uses the complex frequency shifted stretching function and is based on the simple concept of the recursive evaluation of an integral avoiding the calculation of time derivatives. This recursive integration PML is simple to implement, efficient and exhibits a modest gain in performance over the convolutional PML without requiring any extra computational resources or an increase in the algorithmic complexity of the PML implementation.