FDTD (Finite-Difference Time-Domain)

FDTD is a numerical method for solving Maxwell's equations in the time domain, used for precisely modeling electromagnetic wave propagation in structures with dimensions comparable to the wavelength of light.

How does FDTD work?

The method divides space and time into a grid of discrete cells (a Yee grid) and calculates the electric and magnetic fields at every point, step by step. Unlike ray tracing, FDTD accounts for wave phenomena — diffraction, interference, and resonance — making it accurate for nanometer

• and micrometer-scale structures, at the cost of much greater computational demands.

Applications

FDTD is used in designing photonic integrated circuits (PICs), analyzing grating couplers, ring resonators, and modulators, as well as in research on photonic crystals, plasmonics, and optical nanostructures.

Related terms

BPM

Optical waveguide

Photonic crystals