tidy3d.GridSpec

tidy3d.GridSpec#

class GridSpec[source]#

Bases: Tidy3dBaseModel

Collective grid specification for all three dimensions.

Parameters:

  • attrs (dict = {}) – Dictionary storing arbitrary metadata for a Tidy3D object. This dictionary can be freely used by the user for storing data without affecting the operation of Tidy3D as it is not used internally. Note that, unlike regular Tidy3D fields, attrs are mutable. For example, the following is allowed for setting an attr obj.attrs['foo'] = bar. Also note that Tidy3D` will raise a TypeError if attrs contain objects that can not be serialized. One can check if attrs are serializable by calling obj.json().

  • grid_x (Union[UniformGrid, CustomGrid, AutoGrid, CustomGridBoundaries] = AutoGrid(attrs={}, type='AutoGrid', min_steps_per_wvl=10.0, max_scale=1.4, dl_min=0.0, mesher=GradedMesher(attrs={},, type='GradedMesher'))) – Grid specification along x-axis

  • grid_y (Union[UniformGrid, CustomGrid, AutoGrid, CustomGridBoundaries] = AutoGrid(attrs={}, type='AutoGrid', min_steps_per_wvl=10.0, max_scale=1.4, dl_min=0.0, mesher=GradedMesher(attrs={},, type='GradedMesher'))) – Grid specification along y-axis

  • grid_z (Union[UniformGrid, CustomGrid, AutoGrid, CustomGridBoundaries] = AutoGrid(attrs={}, type='AutoGrid', min_steps_per_wvl=10.0, max_scale=1.4, dl_min=0.0, mesher=GradedMesher(attrs={},, type='GradedMesher'))) – Grid specification along z-axis

  • wavelength (Optional[float] = None) – [units = um]. Free-space wavelength for automatic nonuniform grid. It can be ‘None’ if there is at least one source in the simulation, in which case it is defined by the source central frequency. Note: it only takes effect when at least one of the three dimensions uses AutoGrid.

  • override_structures (Tuple[Annotated[Union[tidy3d.components.structure.Structure, tidy3d.components.structure.MeshOverrideStructure], FieldInfo(default=PydanticUndefined, discriminator='type', extra={})], ...] = ()) – A set of structures that is added on top of the simulation structures in the process of generating the grid. This can be used to refine the grid or make it coarser depending than the expected need for higher/lower resolution regions. Note: it only takes effect when at least one of the three dimensions uses AutoGrid.

  • snapping_points (Tuple[Tuple[float, float, float], ...] = ()) – A set of points that enforce grid boundaries to pass through them. However, some points might be skipped if they are too close. Note: it only takes effect when at least one of the three dimensions uses AutoGrid.

Example

>>> uniform = UniformGrid(dl=0.1)
>>> custom = CustomGrid(dl=[0.2, 0.2, 0.1, 0.1, 0.1, 0.2, 0.2])
>>> auto = AutoGrid(min_steps_per_wvl=12)
>>> grid_spec = GridSpec(grid_x=uniform, grid_y=custom, grid_z=auto, wavelength=1.5)

See also

UniformGrid

Uniform 1D grid.

AutoGrid

Specification for non-uniform grid along a given dimension.

Notebooks:
Lectures:

Attributes

auto_grid_used

True if any of the three dimensions uses AutoGrid.

custom_grid_used

True if any of the three dimensions uses CustomGrid.

override_structures_used

Along each axis, True if any override structure is used.

attrs

Methods

auto([wavelength, min_steps_per_wvl, ...])

Use the same AutoGrid along each of the three directions.

from_grid(grid)

Import grid directly from another simulation, e.g. grid_spec = GridSpec.from_grid(sim.grid).

make_grid(structures, symmetry, periodic, ...)

Make the entire simulation grid based on some simulation parameters.

uniform(dl)

Use the same UniformGrid along each of the three directions.

wavelength_from_sources(sources)

Define a wavelength based on supplied sources.

Inherited Common Usage

grid_x#
grid_y#
grid_z#
wavelength#
override_structures#
snapping_points#
property auto_grid_used#

True if any of the three dimensions uses AutoGrid.

property custom_grid_used#

True if any of the three dimensions uses CustomGrid.

static wavelength_from_sources(sources)[source]#

Define a wavelength based on supplied sources. Called if auto mesh is used and self.wavelength is None.

property override_structures_used#

Along each axis, True if any override structure is used. However, it is still False if only MeshOverrideStructure is supplied, and their dl[axis] all take the None value.

make_grid(structures, symmetry, periodic, sources, num_pml_layers)[source]#

Make the entire simulation grid based on some simulation parameters.

Parameters:

  • structures (List[Structure]) – List of structures present in the simulation. The first structure must be the simulation geometry with the simulation background medium.

  • symmetry (Tuple[Symmetry, Symmetry, Symmetry]) – Reflection symmetry across a plane bisecting the simulation domain normal to each of the three axes.

  • sources (List[SourceType]) – List of sources.

  • num_pml_layers (List[Tuple[float, float]]) – List containing the number of absorber layers in - and + boundaries.

Returns:

Entire simulation grid.

Return type:

Grid

classmethod from_grid(grid)[source]#

Import grid directly from another simulation, e.g. grid_spec = GridSpec.from_grid(sim.grid).

classmethod auto(wavelength=None, min_steps_per_wvl=10.0, max_scale=1.4, override_structures=(), snapping_points=(), dl_min=0.0, mesher=GradedMesher(attrs={}, type='GradedMesher'))[source]#

Use the same AutoGrid along each of the three directions.

Parameters:

  • wavelength (pd.PositiveFloat, optional) – Free-space wavelength for automatic nonuniform grid. It can be ‘None’ if there is at least one source in the simulation, in which case it is defined by the source central frequency.

  • min_steps_per_wvl (pd.PositiveFloat, optional) – Minimal number of steps per wavelength in each medium.

  • max_scale (pd.PositiveFloat, optional) – Sets the maximum ratio between any two consecutive grid steps.

  • override_structures (List[StructureType]) – A list of structures that is added on top of the simulation structures in the process of generating the grid. This can be used to refine the grid or make it coarser depending than the expected need for higher/lower resolution regions.

  • snapping_points (Tuple[Coordinate, ...]) – A set of points that enforce grid boundaries to pass through them.

  • dl_min (pd.NonNegativeFloat) – Lower bound of grid size.

  • mesher (MesherType = GradedMesher()) – The type of mesher to use to generate the grid automatically.

Returns:

GridSpec with the same automatic nonuniform grid settings in each direction.

Return type:

GridSpec

classmethod uniform(dl)[source]#

Use the same UniformGrid along each of the three directions.

Parameters:

dl (float) – Grid size for uniform grid generation.

Returns:

GridSpec with the same uniform grid size in each direction.

Return type:

GridSpec

__hash__()#

Hash method.