Multigrid FDTD with Chombo

We describe a parallel, multiscale, multigrid, finite-difference time-domain (FDTD) code for simulating electromagnetic wave propagation in two-dimensional systems involving Lorentz and Drude media. We compare multigrid leapfrog time-stepping procedures and analyze the efficacy and scalability of multigrid use in FDTD. We have implemented the code using Chombo, an object-oriented toolkit for finite-difference methods on block-structured, adaptively refined rectangular grids. We discuss the advantages of this high-level approach, as opposed to the direct use of message-passing libraries.