How do I set a total-field scattered-field (TFSF) source?

Date	Category
2023-12-11 15:20:00	Sources

The total-field scattered-field (TFSF) source injects a plane wave in a finite region. The example below illustrates how to define the tidy3d.TFSF within a simulation.

# Source bandwidth.
pulse = tidy3d.GaussianPulse(freq0=200e12, fwidth=20e12)

# Source definition
tfsf_source = tidy3d.TFSF(
  center=(0, 0, 5),
  size=(3, 3, 0),
  source_time=pulse,
  direction='-',
  pol_angle=np.pi / 2,
  angle_theta=np.pi / 4,
  angle_phi=0,
  injection_axis=2,
  name="tfsf_source",
)

Use the center and size parameters to set the source position and dimension, then adjust the source_time dependence using tidy3d.GaussianPulse. The direction parameter specifies propagation in the positive or negative direction of the injection axis. You can change the light polarization using pol_angle, and adjust the propagation axis direction with angle_theta and angle_phito control the polar and azimuth angles. The injection_axis parameter specifies injection along the x (0), y (1), or z (2) direction.

See this notebook to an example on setting up a tidy3d.TFSF source.