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tidy3d.Lorentz

tidy3d.Lorentz#

class Lorentz[source]#

Bases: DispersiveMedium

A dispersive medium described by the Lorentz model.

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 (\(\epsilon_\infty\)).

  • coeffs (Tuple[Tuple[float, float, pydantic.v1.types.NonNegativeFloat], ...]) – [units = (None (relative permittivity), Hz, Hz)]. List of (\(\Delta\epsilon_i, f_i, \delta_i\)) values for model.

Notes

The frequency-dependence of the complex-valued permittivity is described by:

\[\epsilon(f) = \epsilon_\infty + \sum_i \frac{\Delta\epsilon_i f_i^2}{f_i^2 - 2jf\delta_i - f^2}\]

Example

>>> lorentz_medium = Lorentz(eps_inf=2.0, coeffs=[(1,2,3), (4,5,6)])
>>> eps = lorentz_medium.eps_model(200e12)

See also

Notebooks
Lectures

Attributes

Methods

eps_model(frequency)

Complex-valued permittivity as a function of frequency.

from_nk(n, k, freq, **kwargs)

Convert n and k values at frequency freq to a single-pole Lorentz medium.
eps_inf#
coeffs#
eps_model(frequency)[source]#

Complex-valued permittivity as a function of frequency.

classmethod from_nk(n, k, freq, **kwargs)[source]#

Convert n and k values at frequency freq to a single-pole Lorentz medium.

Parameters:

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

  • k (float = 0) – Imaginary part of refrative index.

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

Returns:

Lorentz medium having refractive index n+ik at frequency freq.

Return type:

Lorentz

__hash__()#

Hash method.