Optimal parameters of a Perfectly-Matched Layer for nanophotonics problems

In the solution of evolutionary problems in electrodynamics and in the numerical Finite Difference Time Domain (FDTD) method with Perfectly Matched Layer (PML) boundary conditions, reflections of electromagnetic waves from the boundaries inevitably arise. The nature and magnitude of these reflections depend on many parameters. We have demonstrated the method of calculating the coefficient of reflection for the one-dimensional (1D) case. A comparison with real 3D numerical experiments shows the high accuracy of the calculated theoretical reflection. On this basis, a method for selecting the optimal parameters of a perfectly matched layer is proposed.