flex_rf.tidy3d.AutoGrid

Type: class │ Base(s): AbstractAutoGrid

Description

Specification for non-uniform grid along a given dimension.

Notes

Practical Advice

Recommended min_steps_per_wvl values:

10 (default): Quick estimates and sanity checks only.
15-20: Good accuracy for most simulations. Verify convergence by comparing results at two resolutions.
Higher: Only if convergence tests show the result hasn’t settled. Can be expensive — use judiciously.

Ensure that geometric features (thin slabs, narrow gaps) are covered by at least 2 grid cells. For a typical 220 nm SOI waveguide, fewer than 10 cells in z is often sufficient.

Example(s)

grid_1d = AutoGrid(min_steps_per_wvl=16, max_scale=1.4)

Parameters

max_scale [float] = 1.4

Sets the maximum ratio between any two consecutive grid steps.

mesher [MesherType] = factory: GradedMesher

The type of mesher to use to generate the grid automatically.

dl_min [NonNegativeFloat | None] = None

Lower bound of the grid size along this dimension regardless of structures present in the simulation, including override structures with enforced=True. It is a soft bound, meaning that the actual minimal grid size might be slightly smaller. If None or 0, a heuristic lower bound value will be applied.

min_steps_per_wvl [float] = 10.0

Minimal number of steps per wavelength in each medium.

min_steps_per_sim_size [float] = 10.0

Minimal number of steps per longest edge length of simulation domain bounding box. This is useful when the simulation domain size is subwavelength.

Methods

estimated_min_dl(wavelength: float, structure_list: list[Structure], sim_size: tuple[float, 3])

Estimated minimal grid size along the axis. The actual minimal grid size from mesher might be smaller.