gds_fdtd.modes

gds_fdtd simulation toolbox.

Waveguide mode solving — the second Tier-B enabler. Kernel-level engines need mode profiles at port cross-sections to synthesize sources and decompose recorded fields; ModeSolver is the backend-agnostic protocol (raw permittivity cross-section in, Mode list out) and Tidy3DModeSolver the first backend: tidy3d’s LOCAL mode-solver plugin — pure local math, no cloud tasks, no credits (verified: the 500x220 nm Si strip acceptance case gives n_eff(TE0) = 2.451 at 1.55 um).

The cross-section convention matches grid.rasterize output: eps[u, v] with u, v the two transverse axes, cell-centered, spacings du/dv um.

Functions

waveguide_mode(width_um, height_um, n_core, ...)

Guided modes of a rectangular strip waveguide, offline.

Classes

Mode(n_eff, fields, u, v, wavelength_um)	One guided mode on a transverse cross-section grid.
ModeSolver(*args, **kwargs)	Backend-agnostic mode solver: eps cross-section in, modes out.
Tidy3DModeSolver()	tidy3d's local mode-solver plugin (free, offline, no cloud tasks).