3D space-time subgridding algorithm for FDTD

In this paper we present a FDTD local space-time mesh refinement method for electromagnetic 3D simulations. The algorithm is based on the method developed which is an adaptation to FDTD of the "Adaptative Mesh Refinement" algorithm originally developed for the numerical resolution of hyperbolic conservation laws. The algorithm is only presented in 2 space dimensions with a refinement ratio of 2. Here we propose a generalisation of this method in 3 space dimensions with any refinement ratio. In the first section we explain the broad outlines of the refinement algorithm. Section 2 presents some numerical tests that we performed to check the accuracy and the stability of the method. The last section presents an application to problem of EMC in ignition laser facilities chambers.