opencl_fdfd

opencl_fdfd is a 3D Finite Difference Frequency Domain (FDFD) solver implemented in Python and OpenCL.

Capabilities

• Arbitrary distributions of the following:
  • Dielectric constant (epsilon)
  • Magnetic permeabilty (mu)
  • Perfect electric conductor (PEC)
  • Perfect magnetic conductor (PMC)
• Variable-sized rectangular grids
  • Stretched-coordinate PMLs (complex cell sizes allowed)

Currently, only periodic boundary conditions are included. PEC/PMC boundaries can be implemented by drawing PEC/PMC cells near the edges. Bloch boundary conditions are not included but wouldn't be very hard to add.

The default solver (opencl_fdfd.cg_solver(...)) located in main.py implements the E-field wave operator directly (ie, as a list of OpenCL instructions rather than a matrix). Additionally, there is a slower (and slightly more versatile) sovler in csr.py which attempts to solve an arbitrary sparse matrix in compressed sparse row (CSR) format using the same conjugate gradient method as the default solver. The CSR solver is significantly slower, but can be very useful for testing alternative formulations of the FDFD wave equation.

Currently, this solver only uses a single GPU or other OpenCL accelerator; generalization to multiple GPUs should be pretty straightforward (ie, just copy over edge values during the matrix multiplication step).

Dependencies:

• python 3 (written and tested with 3.5)
• numpy
• pyopencl
• jinja2
• fdfd_tools