tidy3d.components.base_sim.simulation.AbstractSimulation

class AbstractSimulation

Bases: Box, ABC

Base class for simulation classes of different solvers.

Parameters:

• center (Attribute: center) –

  Type	Tuple[float, float, float]
  Default	= (0.0, 0.0, 0.0)
  Units	um
  Description	Center of object in x, y, and z.

• size (Attribute: size) –

  Type	Tuple[NonNegativeFloat, NonNegativeFloat, NonNegativeFloat]
  Default
  Units	um
  Description	Size in x, y, and z directions.

• medium (Attribute: medium) –

  Type	Union[Medium, AnisotropicMedium, PECMedium, PoleResidue, Sellmeier, Lorentz, Debye, Drude, FullyAnisotropicMedium, CustomMedium, CustomPoleResidue, CustomSellmeier, CustomLorentz, CustomDebye, CustomDrude, CustomAnisotropicMedium, PerturbationMedium, PerturbationPoleResidue]
  Default	= Medium(nameNone, frequency_rangeNone, allow_gainFalse, nonlinear_specNone, modulation_specNone, heat_specNone, type’Medium’, permittivity1.0, conductivity0.0)
  Description	Background medium of simulation, defaults to vacuum if not specified.

• structures (Attribute: structures) –

  Type	Tuple[Structure, …]
  Default	= ()
  Description	Tuple of structures present in simulation. Note: Structures defined later in this list override the simulation material properties in regions of spatial overlap.

• symmetry (Attribute: symmetry) –

  Type	Tuple[Literal[0, -1, 1], Literal[0, -1, 1], Literal[0, -1, 1]]
  Default	= (0, 0, 0)
  Description	Tuple of integers defining reflection symmetry across a plane bisecting the simulation domain normal to the x-, y-, and z-axis at the simulation center of each axis, respectively. Each element can be 0 (no symmetry), 1 (even, i.e. ‘PMC’ symmetry) or -1 (odd, i.e. ‘PEC’ symmetry). Note that the vectorial nature of the fields must be taken into account to correctly determine the symmetry value.

• sources (Attribute: sources) –

  Type	Tuple[NoneType, …]
  Default	= ()
  Description	Sources in the simulation.

• boundary_spec (Attribute: boundary_spec) –

  Type	Optional[NoneType]
  Default	= None
  Description	Specification of boundary conditions.

• monitors (Attribute: monitors) –

  Type	Tuple[NoneType, …]
  Default	= ()
  Description	Monitors in the simulation.

• grid_spec (Attribute: grid_spec) –

  Type	Optional[NoneType]
  Default	= None
  Description	Specifications for the simulation grid.

• version (Attribute: version) –

  Type	str
  Default	= 2.6.0rc1
  Description	String specifying the front end version number.

Attributes

scene	Scene instance associated with the simulation.
simulation_bounds	Simulation bounds including auxiliary boundary zones such as PML layers.
simulation_geometry	The entire simulation domain including auxiliary boundary zones such as PML layers.
simulation_structure	Returns structure representing the domain of the simulation.
version	Defines the front end version of tidy3d

Methods

from_scene(scene, **kwargs)	Create a simulation from a :class:.`Scene` instance.
get_monitor_by_name(name)	Return monitor named 'name'.
plot([x, y, z, ax, source_alpha, ...])	Plot each of simulation's components on a plane defined by one nonzero x,y,z coordinate.
plot_boundaries([x, y, z, ax])	Plot the simulation boundary conditions as lines on a plane
plot_monitors([x, y, z, hlim, vlim, alpha, ax])	Plot each of simulation's monitors on a plane defined by one nonzero x,y,z coordinate.
plot_sources([x, y, z, hlim, vlim, alpha, ax])	Plot each of simulation's sources on a plane defined by one nonzero x,y,z coordinate.
plot_structures([x, y, z, ax, hlim, vlim])	Plot each of simulation's structures on a plane defined by one nonzero x,y,z coordinate.
plot_structures_eps([x, y, z, freq, alpha, ...])	Plot each of simulation's structures on a plane defined by one nonzero x,y,z coordinate.
plot_structures_heat_conductivity([x, y, z, ...])	Plot each of simulation's structures on a plane defined by one nonzero x,y,z coordinate.
plot_symmetries([x, y, z, hlim, vlim, ax])	Plot each of simulation's symmetries on a plane defined by one nonzero x,y,z coordinate.

medium

Background medium of simulation, defaults to vacuum if not specified.

See also

Material Library:

The material library is a dictionary containing various dispersive models from real world materials.

Index:

Dispersive and dispersionless Mediums models.

Notebooks:

• Fitting dispersive material models

Lectures:

• Modeling dispersive material in FDTD

GUI:

• Mediums

structures

Tuple of structures present in simulation. Structures defined later in this list override the simulation material properties in regions of spatial overlap.

Example

Simple application reference:

Simulation(
    ...
    structures=[
         Structure(
         geometry=Box(size=(1, 1, 1), center=(0, 0, 0)),
         medium=Medium(permittivity=2.0),
         ),
    ],
    ...
)

Usage Caveats

It is very important to understand the way the dielectric permittivity of the Structure list is resolved by the simulation grid. Without subpixel averaging, the structure geometry in relation to the grid points can lead to its features permittivity not being fully resolved by the simulation.

For example, in the image below, two silicon slabs with thicknesses 150nm and 175nm centered in a grid with spatial discretization \(\Delta z = 25\text{nm}\) will compute equivalently because that grid does not resolve the feature permittivity in between grid points without subpixel averaging.

See also

Structure:

Defines a physical object that interacts with the electromagnetic fields.

subpixel

Subpixel averaging of the permittivity based on structure definition, resulting in much higher accuracy for a given grid size.

Notebooks:

• Visualizing geometries in Tidy3D

Lectures:

• Using FDTD to Compute a Transmission Spectrum

• Dielectric constant assignment on Yee grids

GUI:

• Structures

symmetry

You should set the symmetry parameter in your Simulation object using a tuple of integers defining reflection symmetry across a plane bisecting the simulation domain normal to the x-, y-, and z-axis. Each element can be 0 (no symmetry), 1 (even, i.e. PMC symmetry) or -1 (odd, i.e. PEC symmetry). Note that the vectorial nature of the fields must be considered to determine the symmetry value correctly.

The figure below illustrates how the electric and magnetic field components transform under PEC- and PMC-like symmetry planes. You can refer to this figure when considering whether a source field conforms to a PEC- or PMC-like symmetry axis. This would be helpful, especially when dealing with optical waveguide modes.

sources

boundary_spec

monitors

grid_spec

version

Validating setup

property scene

Scene instance associated with the simulation.

get_monitor_by_name(name)

Return monitor named ‘name’.

property simulation_bounds

Simulation bounds including auxiliary boundary zones such as PML layers.

property simulation_geometry

The entire simulation domain including auxiliary boundary zones such as PML layers. It is identical to Simulation.geometry in the absence of such auxiliary zones.

property simulation_structure

Returns structure representing the domain of the simulation. This differs from Simulation.scene.background_structure in that it has finite extent.

plot(x=None, y=None, z=None, ax=None, source_alpha=None, monitor_alpha=None, hlim=None, vlim=None, **patch_kwargs)

Plot each of simulation’s components on a plane defined by one nonzero x,y,z coordinate.

Parameters:

• x (float = None) – position of plane in x direction, only one of x, y, z must be specified to define plane.

• y (float = None) – position of plane in y direction, only one of x, y, z must be specified to define plane.

• z (float = None) – position of plane in z direction, only one of x, y, z must be specified to define plane.

• source_alpha (float = None) – Opacity of the sources. If None, uses Tidy3d default.

• monitor_alpha (float = None) – Opacity of the monitors. If None, uses Tidy3d default.

• ax (matplotlib.axes._subplots.Axes = None) – Matplotlib axes to plot on, if not specified, one is created.

• hlim (Tuple[float, float] = None) – The x range if plotting on xy or xz planes, y range if plotting on yz plane.

• vlim (Tuple[float, float] = None) – The z range if plotting on xz or yz planes, y plane if plotting on xy plane.

Returns:

The supplied or created matplotlib axes.

Return type:

matplotlib.axes._subplots.Axes

plot_sources(x=None, y=None, z=None, hlim=None, vlim=None, alpha=None, ax=None)

Plot each of simulation’s sources on a plane defined by one nonzero x,y,z coordinate.

Parameters:

• x (float = None) – position of plane in x direction, only one of x, y, z must be specified to define plane.

• y (float = None) – position of plane in y direction, only one of x, y, z must be specified to define plane.

• z (float = None) – position of plane in z direction, only one of x, y, z must be specified to define plane.

• hlim (Tuple[float, float] = None) – The x range if plotting on xy or xz planes, y range if plotting on yz plane.

• vlim (Tuple[float, float] = None) – The z range if plotting on xz or yz planes, y plane if plotting on xy plane.

• alpha (float = None) – Opacity of the sources, If None uses Tidy3d default.

• ax (matplotlib.axes._subplots.Axes = None) – Matplotlib axes to plot on, if not specified, one is created.

Returns:

The supplied or created matplotlib axes.

Return type:

matplotlib.axes._subplots.Axes

plot_monitors(x=None, y=None, z=None, hlim=None, vlim=None, alpha=None, ax=None)

Plot each of simulation’s monitors on a plane defined by one nonzero x,y,z coordinate.

Parameters:

• x (float = None) – position of plane in x direction, only one of x, y, z must be specified to define plane.

• y (float = None) – position of plane in y direction, only one of x, y, z must be specified to define plane.

• z (float = None) – position of plane in z direction, only one of x, y, z must be specified to define plane.

• hlim (Tuple[float, float] = None) – The x range if plotting on xy or xz planes, y range if plotting on yz plane.

• vlim (Tuple[float, float] = None) – The z range if plotting on xz or yz planes, y plane if plotting on xy plane.

• alpha (float = None) – Opacity of the sources, If None uses Tidy3d default.

• ax (matplotlib.axes._subplots.Axes = None) – Matplotlib axes to plot on, if not specified, one is created.

Returns:

The supplied or created matplotlib axes.

Return type:

matplotlib.axes._subplots.Axes

plot_symmetries(x=None, y=None, z=None, hlim=None, vlim=None, ax=None)

Plot each of simulation’s symmetries on a plane defined by one nonzero x,y,z coordinate.

Parameters:

• x (float = None) – position of plane in x direction, only one of x, y, z must be specified to define plane.

• y (float = None) – position of plane in y direction, only one of x, y, z must be specified to define plane.

• z (float = None) – position of plane in z direction, only one of x, y, z must be specified to define plane.

• hlim (Tuple[float, float] = None) – The x range if plotting on xy or xz planes, y range if plotting on yz plane.

• vlim (Tuple[float, float] = None) – The z range if plotting on xz or yz planes, y plane if plotting on xy plane.

• ax (matplotlib.axes._subplots.Axes = None) – Matplotlib axes to plot on, if not specified, one is created.

Returns:

The supplied or created matplotlib axes.

Return type:

matplotlib.axes._subplots.Axes

abstract plot_boundaries(x=None, y=None, z=None, ax=None, **kwargs)

Plot the simulation boundary conditions as lines on a plane

defined by one nonzero x,y,z coordinate.

Parameters:

• x (float = None) – position of plane in x direction, only one of x, y, z must be specified to define plane.

• y (float = None) – position of plane in y direction, only one of x, y, z must be specified to define plane.

• z (float = None) – position of plane in z direction, only one of x, y, z must be specified to define plane.

• ax (matplotlib.axes._subplots.Axes = None) – Matplotlib axes to plot on, if not specified, one is created.

• **kwargs – Optional keyword arguments passed to the matplotlib LineCollection. For details on accepted values, refer to Matplotlib’s documentation.

Returns:

The supplied or created matplotlib axes.

Return type:

matplotlib.axes._subplots.Axes

__hash__()

Hash method.

plot_structures(x=None, y=None, z=None, ax=None, hlim=None, vlim=None)

Plot each of simulation’s structures on a plane defined by one nonzero x,y,z coordinate.

Parameters:

• x (float = None) – position of plane in x direction, only one of x, y, z must be specified to define plane.

• y (float = None) – position of plane in y direction, only one of x, y, z must be specified to define plane.

• z (float = None) – position of plane in z direction, only one of x, y, z must be specified to define plane.

• ax (matplotlib.axes._subplots.Axes = None) – Matplotlib axes to plot on, if not specified, one is created.

• hlim (Tuple[float, float] = None) – The x range if plotting on xy or xz planes, y range if plotting on yz plane.

• vlim (Tuple[float, float] = None) – The z range if plotting on xz or yz planes, y plane if plotting on xy plane.

Returns:

The supplied or created matplotlib axes.

Return type:

matplotlib.axes._subplots.Axes

plot_structures_eps(x=None, y=None, z=None, freq=None, alpha=None, cbar=True, reverse=False, ax=None, hlim=None, vlim=None)

Plot each of simulation’s structures on a plane defined by one nonzero x,y,z coordinate. The permittivity is plotted in grayscale based on its value at the specified frequency.

Parameters:

• x (float = None) – position of plane in x direction, only one of x, y, z must be specified to define plane.

• y (float = None) – position of plane in y direction, only one of x, y, z must be specified to define plane.

• z (float = None) – position of plane in z direction, only one of x, y, z must be specified to define plane.

• freq (float = None) – Frequency to evaluate the relative permittivity of all mediums. If not specified, evaluates at infinite frequency.

• reverse (bool = False) – If False, the highest permittivity is plotted in black. If True, it is plotteed in white (suitable for black backgrounds).

• cbar (bool = True) – Whether to plot a colorbar for the relative permittivity.

• alpha (float = None) – Opacity of the structures being plotted. Defaults to the structure default alpha.

• ax (matplotlib.axes._subplots.Axes = None) – Matplotlib axes to plot on, if not specified, one is created.

• hlim (Tuple[float, float] = None) – The x range if plotting on xy or xz planes, y range if plotting on yz plane.

• vlim (Tuple[float, float] = None) – The z range if plotting on xz or yz planes, y plane if plotting on xy plane.

Returns:

The supplied or created matplotlib axes.

Return type:

matplotlib.axes._subplots.Axes

plot_structures_heat_conductivity(x=None, y=None, z=None, alpha=None, cbar=True, reverse=False, ax=None, hlim=None, vlim=None)

Plot each of simulation’s structures on a plane defined by one nonzero x,y,z coordinate. The permittivity is plotted in grayscale based on its value at the specified frequency.

Parameters:

• x (float = None) – position of plane in x direction, only one of x, y, z must be specified to define plane.

• y (float = None) – position of plane in y direction, only one of x, y, z must be specified to define plane.

• z (float = None) – position of plane in z direction, only one of x, y, z must be specified to define plane.

• freq (float = None) – Frequency to evaluate the relative permittivity of all mediums. If not specified, evaluates at infinite frequency.

• reverse (bool = False) – If False, the highest permittivity is plotted in black. If True, it is plotteed in white (suitable for black backgrounds).

• cbar (bool = True) – Whether to plot a colorbar for the relative permittivity.

• alpha (float = None) – Opacity of the structures being plotted. Defaults to the structure default alpha.

• ax (matplotlib.axes._subplots.Axes = None) – Matplotlib axes to plot on, if not specified, one is created.

• hlim (Tuple[float, float] = None) – The x range if plotting on xy or xz planes, y range if plotting on yz plane.

• vlim (Tuple[float, float] = None) – The z range if plotting on xz or yz planes, y plane if plotting on xy plane.

Returns:

The supplied or created matplotlib axes.

Return type:

matplotlib.axes._subplots.Axes

classmethod from_scene(scene, **kwargs)

Create a simulation from a :class:.`Scene` instance. Must provide additional parameters to define a valid simulation (for example, size, run_time, grid_spec, etc).

Parameters:

• scene (:class:.`Scene`) – Scene containing structures information.

• **kwargs – Other arguments