How do I set a GaussianBeam?

Date	Category
2023-12-11 14:19:04	Sources

The source tidy3d.GaussianBeam is a Guassian distribution on a finite extent plane. The example below illustrates how to define the tidy3d.GaussianBeam within a simulation.

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

# Source definition
gauss_source = tidy3d.GaussianBeam(
  center=(0, -5, 0),
  size=(0, 3, 3),
  source_time=pulse,
  direction='+',
  pol_angle=0,
  angle_theta=0,
  angle_phi=0,
  waist_radius=1.0,
  waist_distance=-2.5,
  name="gauss_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. In this example, the radius of the beam at the waist position was adjusted to 1\(\mu\)m using the waist_radius parameter. When waist_distance is positive (negative) the waist is behind (front) the source plane.

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