Basic Materials and Objects

In FDTDX, simulation objects can have a material, which defines the permittivity, permeability and conductivity of the object.

Currently neither dispersion nor non-linear materials are implemented. The implementation of dispersion is scheduled in the near-mid future and afterwards an implementation of non-linear materials will follow.

import fdtdx

material = fdtdx.Material()
print(material)

Material(
  permittivity=#1.0, 
  permeability=#1.0, 
  electric_conductivity=#0.0, 
  magnetic_conductivity=#0.0
)

The default material above with no parameters represents free space with a relative permittivity and permeability of 1. These values can be freely set by a user.

material2 = fdtdx.Material(permittivity=2.5, permeability=1.7)
print(material2)

Material(
  permittivity=#2.5, 
  permeability=#1.7, 
  electric_conductivity=#0.0, 
  magnetic_conductivity=#0.0
)

fdtdx.UniformMaterial

The most basic and also probably most useful object is the UniformMaterialObject. As the name suggests, it has a single material. Importantly, every object in FDTDX needs to have a unique name! If no name is provided, then some name is chosen programmatically.

uniform_obj = fdtdx.UniformMaterialObject(
    partial_real_shape=(0.6e-6, 0.6e-6, 0.6e-6),  # size of the object in meters
    material=material,  # material
    name="Uniform Material",  # name of the object, optional
)
print(uniform_obj)

UniformMaterialObject(
  partial_real_shape=#(6e-07, 6e-07, 6e-07), 
  partial_grid_shape=#(None, None, None), 
  color=#(0.8470588235294118, 0.8627450980392157, 0.8392156862745098), 
  name=#Uniform Material, 
  max_random_real_offsets=#(0, 0, 0), 
  max_random_grid_offsets=#(0, 0, 0), 
  _grid_slice_tuple=#((-1, -1), (-1, -1), (-1, -1)), 
  placement_order=#0, 
  material=Material(
    permittivity=#1.0, 
    permeability=#1.0, 
    electric_conductivity=#0.0, 
    magnetic_conductivity=#0.0
  )
)

There also exist Objects with more elaborate material distributions, but for the quickstart we will only cover this most basic material.