How do I specify a Port in the scattering matrix calculation?

Date	Category
2023-12-20 18:27:43	Scattering Matrix

To compute scattering matrix parameters, you need to create a base tidy3d.Simulation (without the modal sources or monitors used to compute S-parameters) and include tidy3d.plugins.smatrix.Port objects. These ports will be converted into modal sources and monitors later, so they require both some mode specification and a definition of the direction that points into the system. You should also give them names to refer to later. For example:

from tidy3d.plugins.smatrix.smatrix import Port

num_modes = 1

# Port definition.
port_right_top = Port(
  center=[-5, 3, 0],
  size=[0, 4, 2],
  mode_spec=tidy3d.ModeSpec(num_modes=num_modes),
  direction="-",
  name="right_top",
)