tidy3d.plugins.adjoint.JaxCustomMedium

class JaxCustomMedium

Bases: CustomMedium, AbstractJaxMedium

A CustomMedium registered with jax. Note: The gradient calculation assumes uniform field across the pixel. Therefore, the accuracy degrades as the pixel size becomes large with respect to the field variation.

Parameters:

• name (Attribute: name) –

  Type	Optional[str]
  Default	= None
  Description	Optional unique name for medium.

• frequency_range (Attribute: frequency_range) –

  Type	Optional[Tuple[float, float]]
  Default	= None
  Units	(Hz, Hz)
  Description	Optional range of validity for the medium.

• allow_gain (Attribute: allow_gain) –

  Type	bool
  Default	= False
  Description	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 (Attribute: nonlinear_spec) –

  Type	Union[NonlinearSpec, NonlinearSusceptibility]
  Default	= None
  Description	Nonlinear spec applied on top of the base medium properties.

• modulation_spec (Attribute: modulation_spec) –

  Type	Optional[ModulationSpec]
  Default	= None
  Description	Modulation spec applied on top of the base medium properties.

• heat_spec (Attribute: heat_spec) –

  Type	Union[FluidSpec, SolidSpec, NoneType]
  Default	= None
  Description	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.

• interp_method (Attribute: interp_method) –

  Type	Literal[‘nearest’, ‘linear’]
  Default	= nearest
  Description	Interpolation method to obtain permittivity values that are not supplied at the Yee grids; For grids outside the range of the supplied data, extrapolation will be applied. When the extrapolated value is smaller (greater) than the minimal (maximal) of the supplied data, the extrapolated value will take the minimal (maximal) of the supplied data.

• subpixel (Attribute: subpixel) –

  Type	bool
  Default	= False
  Description	If True and simulation’s subpixel is also True, applies subpixel averaging of the permittivity on the interface of the structure, including exterior boundary and intersection interfaces with other structures.

• eps_dataset (Attribute: eps_dataset) –

  Type	Optional[JaxPermittivityDataset]
  Default	= None
  Description	User-supplied dataset containing complex-valued permittivity as a function of space. Permittivity distribution over the Yee-grid will be interpolated based on the data nearest to the grid location.

• permittivity (Attribute: permittivity) –

  Type	Optional[SpatialDataArray]
  Default	= None
  Units	None (relative permittivity)
  Description	Spatial profile of relative permittivity.

• conductivity (Attribute: conductivity) –

  Type	Optional[SpatialDataArray]
  Default	= None
  Units	S/um
  Description	Spatial profile Electric conductivity. Defined such that the imaginary part of the complex permittivity at angular frequency omega is given by conductivity/omega.

Attributes

Methods

store_vjp(grad_data_fwd, grad_data_adj, ...)

Returns the gradient of the medium parameters given forward and adjoint field data.

eps_dataset

store_vjp(grad_data_fwd, grad_data_adj, sim_bounds, wvl_mat, inside_fn)

Returns the gradient of the medium parameters given forward and adjoint field data.

__hash__()

Hash method.