tidy3d.FieldTimeMonitor

class FieldTimeMonitor

Bases: AbstractFieldMonitor, TimeMonitor

Monitor that records electromagnetic fields in the time domain.

Parameters:

• center (Attribute: center) –

  Type	Tuple[float, float, float]
  Default	= (0.0, 0.0, 0.0)
  Units	um
  Description	Center of object in x, y, and z.

• size (Attribute: size) –

  Type	Tuple[NonNegativeFloat, NonNegativeFloat, NonNegativeFloat]
  Default
  Units	um
  Description	Size in x, y, and z directions.

• name (Attribute: name) –

  Type	ConstrainedStrValue
  Default
  Description	Unique name for monitor.

• interval_space (Attribute: interval_space) –

  Type	Tuple[PositiveInt, PositiveInt, PositiveInt]
  Default	= (1, 1, 1)
  Description	Number of grid step intervals between monitor recordings. If equal to 1, there will be no downsampling. If greater than 1, the step will be applied, but the first and last point of the monitor grid are always included.

• colocate (Attribute: colocate) –

  Type	bool
  Default	= True
  Description	Toggle whether fields should be colocated to grid cell boundaries (i.e. primal grid nodes).

• start (Attribute: start) –

  Type	NonNegativeFloat
  Default	= 0.0
  Units	sec
  Description	Time at which to start monitor recording.

• stop (Attribute: stop) –

  Type	Optional[NonNegativeFloat]
  Default	= None
  Units	sec
  Description	Time at which to stop monitor recording. If not specified, record until end of simulation.

• interval (Attribute: interval) –

  Type	Optional[PositiveInt]
  Default	= None
  Description	Sampling rate of the monitor: number of time steps between each measurement. Set interval to 1 for the highest possible resolution in time. Higher integer values downsample the data by measuring every interval time steps. This can be useful for reducing data storage as needed by the application.

• fields (Attribute: fields) –

  Type	Tuple[Literal[‘Ex’, ‘Ey’, ‘Ez’, ‘Hx’, ‘Hy’, ‘Hz’], …]
  Default	= [‘Ex’, ‘Ey’, ‘Ez’, ‘Hx’, ‘Hy’, ‘Hz’]
  Description	Collection of field components to store in the monitor.

Notes

FieldTimeMonitor objects are best used to monitor the time dependence of the fields at a single point, but they can also be used to create “animations” of the field pattern evolution.

To create an animation, we need to capture the frames at different time instances of the simulation. This can be done by using a FieldTimeMonitor. Usually a FDTD simulation contains a large number of time steps and grid points. Recording the field at every time step and grid point will result in a large dataset. For the purpose of making animations, this is usually unnecessary.

Example

>>> monitor = FieldTimeMonitor(
...     center=(1,2,3),
...     size=(2,2,2),
...     fields=['Hx'],
...     start=1e-13,
...     stop=5e-13,
...     interval=2,
...     colocate=True,
...     name='movie_monitor')

See also

Notebooks

• First walkthrough: Usage in a basic simulation flow.

• Creating FDTD animations.

Attributes

Methods

storage_size(num_cells, tmesh)

Size of monitor storage given the number of points after discretization.

storage_size(num_cells, tmesh)

Size of monitor storage given the number of points after discretization.

__hash__()

Hash method.