tidy3d.PoleResidue

class tidy3d.PoleResidue(*, name: str = None, frequency_range: Tuple[float, float] = None, allow_gain: bool = False, nonlinear_spec: Union[tidy3d.components.medium.NonlinearSpec, tidy3d.components.medium.NonlinearSusceptibility] = None, modulation_spec: tidy3d.components.time_modulation.ModulationSpec = None, heat_spec: Optional[Union[tidy3d.components.heat_spec.FluidSpec, tidy3d.components.heat_spec.SolidSpec]] = None, type: Literal['PoleResidue'] = 'PoleResidue', eps_inf: pydantic.v1.types.PositiveFloat = 1.0, poles: Tuple[Tuple[Union[tidy3d.components.types.tidycomplex, tidy3d.components.types.ComplexNumber], Union[tidy3d.components.types.tidycomplex, tidy3d.components.types.ComplexNumber]], ...] = ())

Bases: tidy3d.components.medium.DispersiveMedium

A dispersive medium described by the pole-residue pair model. The frequency-dependence of the complex-valued permittivity is described by:

Parameters

• 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 (bool = False) – Allow the medium to be active. Caution: simulations with a gain medium are unstable, and are likely to diverge.Simulations where ‘allow_gain’ is set to ‘True’ will still be charged even if diverged. Monitor data up to the divergence point will still be returned and can be useful in some cases.

• 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.

• eps_inf (PositiveFloat = 1.0) – [units = None (relative permittivity)]. Relative permittivity at infinite frequency (\(\epsilon_\infty\)).

• poles (Tuple[Tuple[Union[tidy3d.components.types.tidycomplex, tidy3d.components.types.ComplexNumber], Union[tidy3d.components.types.tidycomplex, tidy3d.components.types.ComplexNumber]], ...] = ()) – [units = (rad/sec, rad/sec)]. Tuple of complex-valued (\(a_i, c_i\)) poles for the model.

Note

\[\epsilon(\omega) = \epsilon_\infty - \sum_i \left[\frac{c_i}{j \omega + a_i} + \frac{c_i^*}{j \omega + a_i^*}\right]\]

Example

>>> pole_res = PoleResidue(eps_inf=2.0, poles=[((-1+2j), (3+4j)), ((-5+6j), (7+8j))])
>>> eps = pole_res.eps_model(200e12)

__init__(**kwargs)

Init method, includes post-init validators.

Methods

Hz_to_angular_freq(f_hz)	Convert frequency in unit of Hz to rad/s.
__init__(**kwargs)	Init method, includes post-init validators.
add_type_field()	Automatically place "type" field with model name in the model field dictionary.
angular_freq_to_Hz(f_rad)	Convert frequency in unit of rad/s to Hz.
angular_freq_to_eV(f_rad)	Convert frequency in unit of rad/s to eV.
complex_to_tuple(value)	Convert a complex number to a tuple of real and imaginary parts.
construct([_fields_set])	Creates a new model setting __dict__ and __fields_set__ from trusted or pre-validated data.
copy(**kwargs)	Copy a Tidy3dBaseModel.
dict(*[, include, exclude, by_alias, ...])	Generate a dictionary representation of the model, optionally specifying which fields to include or exclude.
dict_from_file(fname[, group_path])	Loads a dictionary containing the model from a .yaml, .json, .hdf5, or .hdf5.gz file.
dict_from_hdf5(fname[, group_path, ...])	Loads a dictionary containing the model contents from a .hdf5 file.
dict_from_hdf5_gz(fname[, group_path, ...])	Loads a dictionary containing the model contents from a .hdf5.gz file.
dict_from_json(fname)	Load dictionary of the model from a .json file.
dict_from_yaml(fname)	Load dictionary of the model from a .yaml file.
eV_to_angular_freq(f_eV)	Convert frequency in unit of eV to rad/s.
eps_comp(row, col, frequency)	Single component of the complex-valued permittivity tensor as a function of frequency.
eps_complex_to_eps_sigma(eps_complex, freq)	Convert complex permittivity at frequency freq to permittivity and conductivity values.
eps_complex_to_nk(eps_c)	Convert complex permittivity to n, k values.
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.
eps_sigma_to_eps_complex(eps_real, sigma, freq)	convert permittivity and conductivity to complex permittivity at freq
from_file(fname[, group_path])	Loads a Tidy3dBaseModel from .yaml, .json, .hdf5, or .hdf5.gz file.
from_hdf5(fname[, group_path, custom_decoders])	Loads Tidy3dBaseModel instance to .hdf5 file.
from_hdf5_gz(fname[, group_path, ...])	Loads Tidy3dBaseModel instance to .hdf5.gz file.
from_json(fname, **parse_obj_kwargs)	Load a Tidy3dBaseModel from .json file.
from_lo_to(poles[, eps_inf])	Construct a pole residue model from the LO-TO form (longitudinal and transverse optical modes).
from_medium(medium)	Convert a Medium to a pole residue model.
from_orm(obj)
from_yaml(fname, **parse_obj_kwargs)	Loads Tidy3dBaseModel from .yaml file.
generate_docstring()	Generates a docstring for a Tidy3D mode and saves it to the __doc__ of the class.
get_sub_model(group_path, model_dict)	Get the sub model for a given group path.
get_submodels_by_hash()	Return a dictionary of this object's sub-models indexed by their hash values.
get_tuple_group_name(index)	Get the group name of a tuple element.
get_tuple_index(key_name)	Get the index into the tuple based on its group name.
help([methods])	Prints message describing the fields and methods of a Tidy3dBaseModel.
imag_ep_extrema(poles)	Extrema of Im[eps] in the same unit as poles.
json(*[, include, exclude, by_alias, ...])	Generate a JSON representation of the model, include and exclude arguments as per dict().
lo_to_eps_model(poles, eps_inf, frequency)	Complex permittivity as a function of frequency for a given set of LO-TO coefficients.
nk_model(frequency)	Real and imaginary parts of the refactive index as a function of frequency.
nk_to_eps_complex(n[, k])	Convert n, k to complex permittivity.
nk_to_eps_sigma(n, k, freq)	Convert n, k at frequency freq to permittivity and conductivity values.
parse_file(path, *[, content_type, ...])
parse_obj(obj)
parse_raw(b, *[, content_type, encoding, ...])
plot(freqs[, ax])	Plot n, k of a Medium as a function of frequency.
schema([by_alias, ref_template])
schema_json(*[, by_alias, ref_template])
sigma_model(freq)	Complex-valued conductivity as a function of frequency.
to_file(fname)	Exports Tidy3dBaseModel instance to .yaml, .json, or .hdf5 file
to_hdf5(fname[, custom_encoders])	Exports Tidy3dBaseModel instance to .hdf5 file.
to_hdf5_gz(fname[, custom_encoders])	Exports Tidy3dBaseModel instance to .hdf5.gz file.
to_json(fname)	Exports Tidy3dBaseModel instance to .json file
to_medium()	Convert to a Medium.
to_yaml(fname)	Exports Tidy3dBaseModel instance to .yaml file.
tuple_to_complex(value)	Convert a tuple of real and imaginary parts to complex number.
tuple_to_dict(tuple_values)	How we generate a dictionary mapping new keys to tuple values for hdf5.
update_forward_refs(**localns)	Try to update ForwardRefs on fields based on this Model, globalns and localns.
updated_copy(**kwargs)	Make copy of a component instance with **kwargs indicating updated field values.
validate(value)

Attributes

is_pec	Whether the medium is a PEC.
loss_upper_bound	Upper bound of Im[eps] in frequency_range
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.
pole_residue	Representation of Medium as a pole-residue model.
time_modulated	Whether any component of the medium is time modulated.
eps_inf
poles

class Config

Bases: object

Sets config for all Tidy3dBaseModel objects.

allow_population_by_field_namebool = True

Allow properties to stand in for fields(?).

arbitrary_types_allowedbool = True

Allow types like numpy arrays.

extrastr = ‘forbid’

Forbid extra kwargs not specified in model.

json_encodersDict[type, Callable]

Defines how to encode type in json file.

validate_allbool = True

Validate default values just to be safe.

validate_assignmentbool

Re-validate after re-assignment of field in model.

static Hz_to_angular_freq(f_hz: float)

Convert frequency in unit of Hz to rad/s.

Parameters

f_hz (float) – Frequency in unit of Hz

__eq__(other)

Define == for two Tidy3DBaseModels.

__ge__(other)

define >= for getting unique indices based on hash.

__gt__(other)

define > for getting unique indices based on hash.

__hash__() → int

Hash method.

classmethod __init_subclass__() → None

Things that are done to each of the models.

__iter__() → TupleGenerator

so dict(model) works

__le__(other)

define <= for getting unique indices based on hash.

__lt__(other)

define < for getting unique indices based on hash.

__pretty__(fmt: Callable[[Any], Any], **kwargs: Any) → Generator[Any, None, None]

Used by devtools (https://python-devtools.helpmanual.io/) to provide a human readable representations of objects

__repr_name__() → str

Name of the instance’s class, used in __repr__.

__rich_repr__() → RichReprResult

Get fields for Rich library

__str__()

string representation

classmethod __try_update_forward_refs__(**localns: Any) → None

Same as update_forward_refs but will not raise exception when forward references are not defined.

classmethod add_type_field() → None

Automatically place “type” field with model name in the model field dictionary.

static angular_freq_to_Hz(f_rad: float)

Convert frequency in unit of rad/s to Hz.

Parameters

f_rad (float) – Frequency in unit of rad/s

static angular_freq_to_eV(f_rad: float)

Convert frequency in unit of rad/s to eV.

Parameters

f_rad (float) – Frequency in unit of rad/s

static complex_to_tuple(value: complex) → Tuple[float, float]

Convert a complex number to a tuple of real and imaginary parts.

classmethod construct(_fields_set: Optional[SetStr] = None, **values: Any) → Model

Creates a new model setting __dict__ and __fields_set__ from trusted or pre-validated data. Default values are respected, but no other validation is performed. Behaves as if Config.extra = ‘allow’ was set since it adds all passed values

copy(**kwargs) → tidy3d.components.base.Tidy3dBaseModel

Copy a Tidy3dBaseModel. With deep=True as default.

dict(*, include: Optional[Union[AbstractSetIntStr, MappingIntStrAny]] = None, exclude: Optional[Union[AbstractSetIntStr, MappingIntStrAny]] = None, by_alias: bool = False, skip_defaults: Optional[bool] = None, exclude_unset: bool = False, exclude_defaults: bool = False, exclude_none: bool = False) → DictStrAny

Generate a dictionary representation of the model, optionally specifying which fields to include or exclude.

classmethod dict_from_file(fname: str, group_path: Optional[str] = None) → dict

Loads a dictionary containing the model from a .yaml, .json, .hdf5, or .hdf5.gz file.

Parameters

• fname (str) – Full path to the file to load the Tidy3dBaseModel from.

• group_path (str, optional) – Path to a group inside the file to use as the base level.

Returns

A dictionary containing the model.

Return type

dict

Example

>>> simulation = Simulation.from_file(fname='folder/sim.json') 

classmethod dict_from_hdf5(fname: str, group_path: str = '', custom_decoders: Optional[List[Callable]] = None) → dict

Loads a dictionary containing the model contents from a .hdf5 file.

Parameters

• fname (str) – Full path to the .hdf5 file to load the Tidy3dBaseModel from.

• group_path (str, optional) – Path to a group inside the file to selectively load a sub-element of the model only.

• custom_decoders (List[Callable]) – List of functions accepting (fname: str, group_path: str, model_dict: dict, key: str, value: Any) that store the value in the model dict after a custom decoding.

Returns

Dictionary containing the model.

Return type

dict

Example

>>> sim_dict = Simulation.dict_from_hdf5(fname='folder/sim.hdf5') 

classmethod dict_from_hdf5_gz(fname: str, group_path: str = '', custom_decoders: Optional[List[Callable]] = None) → dict

Loads a dictionary containing the model contents from a .hdf5.gz file.

Parameters

• fname (str) – Full path to the .hdf5.gz file to load the Tidy3dBaseModel from.

• group_path (str, optional) – Path to a group inside the file to selectively load a sub-element of the model only.

• custom_decoders (List[Callable]) – List of functions accepting (fname: str, group_path: str, model_dict: dict, key: str, value: Any) that store the value in the model dict after a custom decoding.

Returns

Dictionary containing the model.

Return type

dict

Example

>>> sim_dict = Simulation.dict_from_hdf5(fname='folder/sim.hdf5.gz') 

classmethod dict_from_json(fname: str) → dict

Load dictionary of the model from a .json file.

Parameters

fname (str) – Full path to the .json file to load the Tidy3dBaseModel from.

Returns

A dictionary containing the model.

Return type

dict

Example

>>> sim_dict = Simulation.dict_from_json(fname='folder/sim.json') 

classmethod dict_from_yaml(fname: str) → dict

Load dictionary of the model from a .yaml file.

Parameters

fname (str) – Full path to the .yaml file to load the Tidy3dBaseModel from.

Returns

A dictionary containing the model.

Return type

dict

Example

>>> sim_dict = Simulation.dict_from_yaml(fname='folder/sim.yaml') 

static eV_to_angular_freq(f_eV: float)

Convert frequency in unit of eV to rad/s.

Parameters

f_eV (float) – Frequency in unit of eV

eps_comp(row: Literal[0, 1, 2], col: Literal[0, 1, 2], frequency: float) → complex

Single component of 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

static eps_complex_to_eps_sigma(eps_complex: complex, freq: float) → Tuple[float, float]

Convert complex permittivity at frequency freq to permittivity and conductivity values.

Parameters

• eps_complex (complex) – Complex-valued relative permittivity.

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

Returns

Real part of relative permittivity & electric conductivity.

Return type

Tuple[float, float]

static eps_complex_to_nk(eps_c: complex) → Tuple[float, float]

Convert complex permittivity to n, k values.

Parameters

eps_c (complex) – Complex-valued relative permittivity.

Returns

Real and imaginary parts of refractive index (n & k).

Return type

Tuple[float, float]

eps_diagonal(frequency: float) → Tuple[complex, complex, complex]

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

Parameters

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

Returns

The diagonal elements of the relative permittivity tensor evaluated at frequency.

Return type

complex

eps_model(frequency: float) → complex

Complex-valued permittivity as a function of frequency.

static eps_sigma_to_eps_complex(eps_real: float, sigma: float, freq: float) → complex

convert permittivity and conductivity to complex permittivity at freq

Parameters

• eps_real (float) – Real-valued relative permittivity.

• sigma (float) – Conductivity.

• freq (float) – Frequency to evaluate permittivity at (Hz). If not supplied, returns real part of permittivity (limit as frequency -> infinity.)

Returns

Complex-valued relative permittivity.

Return type

complex

classmethod from_file(fname: str, group_path: Optional[str] = None, **parse_obj_kwargs) → tidy3d.components.base.Tidy3dBaseModel

Loads a Tidy3dBaseModel from .yaml, .json, .hdf5, or .hdf5.gz file.

Parameters

• fname (str) – Full path to the file to load the Tidy3dBaseModel from.

• group_path (str, optional) – Path to a group inside the file to use as the base level. Only for hdf5 files. Starting / is optional.

• **parse_obj_kwargs – Keyword arguments passed to either pydantic’s parse_obj function when loading model.

Returns

An instance of the component class calling load.

Return type

Tidy3dBaseModel

Example

>>> simulation = Simulation.from_file(fname='folder/sim.json') 

classmethod from_hdf5(fname: str, group_path: str = '', custom_decoders: Optional[List[Callable]] = None, **parse_obj_kwargs) → tidy3d.components.base.Tidy3dBaseModel

Loads Tidy3dBaseModel instance to .hdf5 file.

Parameters

• fname (str) – Full path to the .hdf5 file to load the Tidy3dBaseModel from.

• group_path (str, optional) – Path to a group inside the file to selectively load a sub-element of the model only. Starting / is optional.

• custom_decoders (List[Callable]) – List of functions accepting (fname: str, group_path: str, model_dict: dict, key: str, value: Any) that store the value in the model dict after a custom decoding.

• **parse_obj_kwargs – Keyword arguments passed to pydantic’s parse_obj method.

Example

>>> simulation = Simulation.from_hdf5(fname='folder/sim.hdf5') 

classmethod from_hdf5_gz(fname: str, group_path: str = '', custom_decoders: Optional[List[Callable]] = None, **parse_obj_kwargs) → tidy3d.components.base.Tidy3dBaseModel

Loads Tidy3dBaseModel instance to .hdf5.gz file.

Parameters

• fname (str) – Full path to the .hdf5.gz file to load the Tidy3dBaseModel from.

• group_path (str, optional) – Path to a group inside the file to selectively load a sub-element of the model only. Starting / is optional.

• custom_decoders (List[Callable]) – List of functions accepting (fname: str, group_path: str, model_dict: dict, key: str, value: Any) that store the value in the model dict after a custom decoding.

• **parse_obj_kwargs – Keyword arguments passed to pydantic’s parse_obj method.

Example

>>> simulation = Simulation.from_hdf5_gz(fname='folder/sim.hdf5.gz') 

classmethod from_json(fname: str, **parse_obj_kwargs) → tidy3d.components.base.Tidy3dBaseModel

Load a Tidy3dBaseModel from .json file.

Parameters

fname (str) – Full path to the .json file to load the Tidy3dBaseModel from.

Returns

• Tidy3dBaseModel – An instance of the component class calling load.

• **parse_obj_kwargs – Keyword arguments passed to pydantic’s parse_obj method.

Example

>>> simulation = Simulation.from_json(fname='folder/sim.json') 

classmethod from_lo_to(poles: Tuple[Tuple[float, float, float, float], ...], eps_inf: pydantic.v1.types.PositiveFloat = 1) → tidy3d.components.medium.PoleResidue

Construct a pole residue model from the LO-TO form (longitudinal and transverse optical modes). The LO-TO form is \(\epsilon_\infty \prod_{i=1}^l \frac{\omega_{LO, i}^2 - \omega^2 - i \omega \gamma_{LO, i}}{\omega_{TO, i}^2 - \omega^2 - i \omega \gamma_{TO, i}}\) as given in the paper:

M. Schubert, T. E. Tiwald, and C. M. Herzinger, “Infrared dielectric anisotropy and phonon modes of sapphire,” Phys. Rev. B 61, 8187 (2000).

Parameters

• poles (Tuple[Tuple[float, float, float, float], ...]) – The LO-TO poles, given as list of tuples of the form (omega_LO, gamma_LO, omega_TO, gamma_TO).

• eps_inf (pd.PositiveFloat) – The relative permittivity at infinite frequency.

Returns

The pole residue equivalent of the LO-TO form provided.

Return type

PoleResidue

classmethod from_medium(medium: tidy3d.components.medium.Medium) → tidy3d.components.medium.PoleResidue

Convert a Medium to a pole residue model.

Parameters

medium (Medium) – The medium with permittivity and conductivity to convert.

Returns

The pole residue equivalent.

Return type

PoleResidue

classmethod from_yaml(fname: str, **parse_obj_kwargs) → tidy3d.components.base.Tidy3dBaseModel

Loads Tidy3dBaseModel from .yaml file.

Parameters

• fname (str) – Full path to the .yaml file to load the Tidy3dBaseModel from.

• **parse_obj_kwargs – Keyword arguments passed to pydantic’s parse_obj method.

Returns

An instance of the component class calling from_yaml.

Return type

Tidy3dBaseModel

Example

>>> simulation = Simulation.from_yaml(fname='folder/sim.yaml') 

classmethod generate_docstring() → str

Generates a docstring for a Tidy3D mode and saves it to the __doc__ of the class.

classmethod get_sub_model(group_path: str, model_dict: dict | list) → dict

Get the sub model for a given group path.

get_submodels_by_hash() → Dict[int, List[Union[str, Tuple[str, int]]]]

Return a dictionary of this object’s sub-models indexed by their hash values.

static get_tuple_group_name(index: int) → str

Get the group name of a tuple element.

static get_tuple_index(key_name: str) → int

Get the index into the tuple based on its group name.

help(methods: bool = False) → None

Prints message describing the fields and methods of a Tidy3dBaseModel.

Parameters

methods (bool = False) – Whether to also print out information about object’s methods.

Example

>>> simulation.help(methods=True) 

static imag_ep_extrema(poles: Tuple[Tuple[Union[tidy3d.components.types.tidycomplex, tidy3d.components.types.ComplexNumber], Union[tidy3d.components.types.tidycomplex, tidy3d.components.types.ComplexNumber]], ...]) → tidy3d.components.types.ArrayLike[dtype=float, ndim=1]

Extrema of Im[eps] in the same unit as poles.

Parameters

poles (Tuple[PoleAndResidue, ...]) – Tuple of complex-valued (a_i, c_i) poles for the model.

property is_pec

Whether the medium is a PEC.

json(*, include: Optional[Union[AbstractSetIntStr, MappingIntStrAny]] = None, exclude: Optional[Union[AbstractSetIntStr, MappingIntStrAny]] = None, by_alias: bool = False, skip_defaults: Optional[bool] = None, exclude_unset: bool = False, exclude_defaults: bool = False, exclude_none: bool = False, encoder: Optional[Callable[[Any], Any]] = None, models_as_dict: bool = True, **dumps_kwargs: Any) → str

Generate a JSON representation of the model, include and exclude arguments as per dict().

encoder is an optional function to supply as default to json.dumps(), other arguments as per json.dumps().

static lo_to_eps_model(poles: Tuple[Tuple[float, float, float, float], ...], eps_inf: pydantic.v1.types.PositiveFloat, frequency: float) → complex

Complex permittivity as a function of frequency for a given set of LO-TO coefficients. See from_lo_to in PoleResidue for the detailed form of the model and a reference paper.

Parameters

• poles (Tuple[Tuple[float, float, float, float], ...]) – The LO-TO poles, given as list of tuples of the form (omega_LO, gamma_LO, omega_TO, gamma_TO).

• eps_inf (pd.PositiveFloat) – The relative permittivity at infinite frequency.

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

Returns

The complex permittivity of the given LO-TO model at the given frequency.

Return type

complex

property loss_upper_bound: float

Upper bound of Im[eps] in frequency_range

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 PoleResidue model, it equals sqrt(eps_inf) [https://ieeexplore.ieee.org/document/9082879].

nk_model(frequency: float) → Tuple[float, float]

Real and imaginary parts of the refactive index as a function of frequency.

Parameters

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

Returns

Real part (n) and imaginary part (k) of refractive index of medium.

Return type

Tuple[float, float]

static nk_to_eps_complex(n: float, k: float = 0.0) → complex

Convert n, k to complex permittivity.

Parameters

• n (float) – Real part of refractive index.

• k (float = 0.0) – Imaginary part of refrative index.

Returns

Complex-valued relative permittivity.

Return type

complex

static nk_to_eps_sigma(n: float, k: float, freq: float) → Tuple[float, float]

Convert n, k at frequency freq to permittivity and conductivity values.

Parameters

• n (float) – Real part of refractive index.

• k (float = 0.0) – Imaginary part of refrative index.

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

Returns

Real part of relative permittivity & electric conductivity.

Return type

Tuple[float, float]

plot(freqs: float, ax: matplotlib.axes._axes.Axes = None) → matplotlib.axes._axes.Axes

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

Parameters

• freqs (float) – Frequencies (Hz) to evaluate the medium properties at.

• 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

property pole_residue

Representation of Medium as a pole-residue model.

sigma_model(freq: float) → complex

Complex-valued conductivity as a function of frequency.

Parameters

freq (float) – Frequency to evaluate conductivity at (Hz).

Returns

Complex conductivity at this frequency.

Return type

complex

property time_modulated: bool

Whether any component of the medium is time modulated.

to_file(fname: str) → None

Exports Tidy3dBaseModel instance to .yaml, .json, or .hdf5 file

Parameters

fname (str) – Full path to the .yaml or .json file to save the Tidy3dBaseModel to.

Example

>>> simulation.to_file(fname='folder/sim.json') 

to_hdf5(fname: str, custom_encoders: Optional[List[Callable]] = None) → None

Exports Tidy3dBaseModel instance to .hdf5 file.

Parameters

• fname (str) – Full path to the .hdf5 file to save the Tidy3dBaseModel to.

• custom_encoders (List[Callable]) – List of functions accepting (fname: str, group_path: str, value: Any) that take the value supplied and write it to the hdf5 fname at group_path.

Example

>>> simulation.to_hdf5(fname='folder/sim.hdf5') 

to_hdf5_gz(fname: str, custom_encoders: Optional[List[Callable]] = None) → None

Exports Tidy3dBaseModel instance to .hdf5.gz file.

Parameters

• fname (str) – Full path to the .hdf5.gz file to save the Tidy3dBaseModel to.

• custom_encoders (List[Callable]) – List of functions accepting (fname: str, group_path: str, value: Any) that take the value supplied and write it to the hdf5 fname at group_path.

Example

>>> simulation.to_hdf5_gz(fname='folder/sim.hdf5.gz') 

to_json(fname: str) → None

Exports Tidy3dBaseModel instance to .json file

Parameters

fname (str) – Full path to the .json file to save the Tidy3dBaseModel to.

Example

>>> simulation.to_json(fname='folder/sim.json') 

to_medium() → tidy3d.components.medium.Medium

Convert to a Medium. Requires the pole residue model to only have a pole at 0 frequency, corresponding to a constant conductivity term.

Returns

The non-dispersive equivalent with constant permittivity and conductivity.

Return type

Medium

to_yaml(fname: str) → None

Exports Tidy3dBaseModel instance to .yaml file.

Parameters

fname (str) – Full path to the .yaml file to save the Tidy3dBaseModel to.

Example

>>> simulation.to_yaml(fname='folder/sim.yaml') 

static tuple_to_complex(value: Tuple[float, float]) → complex

Convert a tuple of real and imaginary parts to complex number.

classmethod tuple_to_dict(tuple_values: tuple) → dict

How we generate a dictionary mapping new keys to tuple values for hdf5.

classmethod update_forward_refs(**localns: Any) → None

Try to update ForwardRefs on fields based on this Model, globalns and localns.

updated_copy(**kwargs) → tidy3d.components.base.Tidy3dBaseModel

Make copy of a component instance with **kwargs indicating updated field values.