How FDTDX works#
The solver is compact enough to understand from first principles. These chapters connect Maxwell’s equations to the objects and arrays visible in Python.
Yee-grid time stepping
Staggered fields, leapfrog updates, stability, and numerical dispersion.
Grids and boundaries
Uniform and rectilinear cells, PML, periodic/Bloch faces, PEC/PMC, and symmetry.
Sources and detectors
Temporal profiles, plane/mode/TFSF excitation, phasors, flux, fields, and normalization.
Materials
Loss, dispersion, full tensors, oriented crystals, and subpixel geometry.
Modes and S-parameters
Cross-sectional eigenmodes, overlap amplitudes, port power, and consistent reference planes.
Differentiation
Reverse-mode Maxwell gradients, memory strategies, parameter maps, and objective design.
Pixel and spectral design bases
Swap pixels for cosine, Fourier, or radial waves without changing the FDTD objective.