class tidy3d.TimeMonitor(center, size, t_start=0, t_stop=None, t_step=None, store=('E', 'H'), name=None)

Monitor recording the time-domain fields within a 3D region.

__init__(center, size, t_start=0, t_stop=None, t_step=None, store=('E', 'H'), name=None)


  • center (array_like) – (micron) x, y, and z position of the center of the Monitor.

  • size (array_like) – (micron) Size in x, y, and z.

  • t_start (float, optional) – (second) Starting time of field recording.

  • t_stop (float, optional) – (second) Stopping time of field recording. If None, record until the end of the simulation.

  • t_step (None, optional) – (second) : Time interval at which to record the fields. If None, the fields at every time step are recorded. If a float, it is snapped to an integer multiple of the simulation time step.

  • store (list, optional) – List of attributes to be recorded. Valid entries are 'E', 'H' and 'flux'. If 'flux' is requested, the monitor must be a 2D surface.

  • name (str, optional) – Custom name of the monitor.


Time monitors can result in very large amounts of data if defined over a large spatial region. Recommended usage is either recording the full time evolution of a single point in space, or using t_start and t_stop to record just a few time steps of a larger region.


__init__(center, size[, t_start, t_stop, …])