tidy3d.EMESimulation.smatrix_in_basis

EMESimulation.smatrix_in_basis(smatrix, port_modes, modes1=None, modes2=None, skip_gram_normalization=False)

Express a locally propagated S-matrix in another modal basis.

Pass the mode data for the left and right EME ports, typically (mode_data[0], mode_data[-1]) from the sequence used by propagate(). If modes1 or modes2 is None, that port is left unchanged.

Parameters:

• smatrix (EMESMatrixDataset) – Device S-matrix in the port-mode basis, as returned by propagate(), propagate_from_overlaps(), or compute_smatrix().

• port_modes (tuple[ModeSimulationData | ModeSolverData, …]) – Mode results at the two EME ports.

• modes1 (ElectromagneticFieldData, ModeSolverData, or) – ModeSimulationData, optional New modal bases at port 1 and port 2.

• modes2 (ElectromagneticFieldData, ModeSolverData, or) – ModeSimulationData, optional New modal bases at port 1 and port 2.

• skip_gram_normalization (bool = False) – If False (default), normalize the change of basis so it is correct even for bases that are not orthonormal (linear combinations of port modes, modes on a different grid, or custom fields). If True, skip the Gram normalization and use the plain overlap contraction; this is correct only when the port and new bases each have identity self-overlap in this method’s overlap convention, and otherwise merely recovers the pre-normalization behavior (which may be incorrect).

Returns:

S-matrix in the new basis.

Return type:

EMESMatrixDataset