tidy3d.AnisotropicMedium

class AnisotropicMedium

Bases: AbstractMedium

Diagonally anisotropic medium.

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().

• name (Optional[str] = None) – Optional unique name for medium.

• frequency_range (Optional[Tuple[float, float]] = None) – [units = (Hz, Hz)]. Optional range of validity for the medium.

• allow_gain (Optional[bool] = None) – This field is ignored. Please set allow_gain in each component

• nonlinear_spec (Union[NonlinearSpec, NonlinearSusceptibility] = None) – Nonlinear spec applied on top of the base medium properties.

• modulation_spec (Optional[ModulationSpec] = None) – Modulation spec applied on top of the base medium properties.

• heat_spec (Union[FluidSpec, SolidSpec, NoneType] = None) – Specification of the medium heat properties. They are used for solving the heat equation via the HeatSimulation interface. Such simulations can be used for investigating the influence of heat propagation on the properties of optical systems. Once the temperature distribution in the system is found using HeatSimulation object, Simulation.perturbed_mediums_copy() can be used to convert mediums with perturbation models defined into spatially dependent custom mediums. Otherwise, the heat_spec does not directly affect the running of an optical Simulation.

• xx (Union[Medium, PoleResidue, Sellmeier, Lorentz, Debye, Drude, PECMedium]) – Medium describing the xx-component of the diagonal permittivity tensor.

• yy (Union[Medium, PoleResidue, Sellmeier, Lorentz, Debye, Drude, PECMedium]) – Medium describing the yy-component of the diagonal permittivity tensor.

• zz (Union[Medium, PoleResidue, Sellmeier, Lorentz, Debye, Drude, PECMedium]) – Medium describing the zz-component of the diagonal permittivity tensor.

Notes

Only diagonal anisotropy is currently supported.

Example

>>> medium_xx = Medium(permittivity=4.0)
>>> medium_yy = Medium(permittivity=4.1)
>>> medium_zz = Medium(permittivity=3.9)
>>> anisotropic_dielectric = AnisotropicMedium(xx=medium_xx, yy=medium_yy, zz=medium_zz)

See also

CustomAnisotropicMedium

Diagonally anisotropic medium with spatially varying permittivity in each component.

FullyAnisotropicMedium

Fully anisotropic medium including all 9 components of the permittivity and conductivity tensors.

Notebooks

• Broadband polarizer assisted by anisotropic metamaterial

• Thin film lithium niobate adiabatic waveguide coupler

Attributes

components	Dictionary of diagonal medium components.
elements	The diagonal elements of the medium as a dictionary.
is_pec	Whether the medium is a PEC.
is_time_modulated	Whether any component of the medium is time modulated.
n_cfl	This property computes the index of refraction related to CFL condition, so that the FDTD with this medium is stable when the time step size that doesn't take material factor into account is multiplied by n_cfl.
attrs

Methods

eps_comp(row, col, frequency)	Single component the complex-valued permittivity tensor as a function of frequency.
eps_diagonal(frequency)	Main diagonal of the complex-valued permittivity tensor as a function of frequency.
eps_model(frequency)	Complex-valued permittivity as a function of frequency.
is_comp_pec(comp)	Whether the medium is a PEC.
plot(freqs[, ax])	Plot n, k of a Medium as a function of frequency.
sel_inside(bounds)	Return a new medium that contains the minimal amount data necessary to cover a spatial region defined by bounds.

Inherited Common Usage

xx

yy

zz

allow_gain

property components

Dictionary of diagonal medium components.

property is_time_modulated

Whether any component of the medium is time modulated.

property n_cfl

This property computes the index of refraction related to CFL condition, so that the FDTD with this medium is stable when the time step size that doesn’t take material factor into account is multiplied by n_cfl.

For this medium, it takes the minimal of n_clf in all components.

eps_model(frequency)

Complex-valued permittivity as a function of frequency.

eps_diagonal(frequency)

Main diagonal of the complex-valued permittivity tensor as a function of frequency.

eps_comp(row, col, frequency)

Single component the complex-valued permittivity tensor as a function of frequency.

Parameters:

• row (int) – Component’s row in the permittivity tensor (0, 1, or 2 for x, y, or z respectively).

• col (int) – Component’s column in the permittivity tensor (0, 1, or 2 for x, y, or z respectively).

• frequency (float) – Frequency to evaluate permittivity at (Hz).

Returns:

Element of the relative permittivity tensor evaluated at frequency.

Return type:

complex

plot(freqs, ax=None)

Plot n, k of a Medium as a function of frequency.

property elements

The diagonal elements of the medium as a dictionary.

property is_pec

Whether the medium is a PEC.

is_comp_pec(comp)

Whether the medium is a PEC.

sel_inside(bounds)

Return a new medium that contains the minimal amount data necessary to cover a spatial region defined by bounds.

Parameters:

bounds (Tuple[float, float, float], Tuple[float, float float]) – Min and max bounds packaged as (minx, miny, minz), (maxx, maxy, maxz).

Returns:

AnisotropicMedium with reduced data.

Return type:

AnisotropicMedium

__hash__()

Hash method.