DirectionalCouplerModel

class photonforge.DirectionalCouplerModel(t=2**-0.5, c=-1j * 2**-0.5, i=0, r=0, ports=None)

Analytic model for a 4-port directional coupler

\[\begin{split}S = \begin{bmatrix} r & i & t & c \\ i & r & c & t \\ t & c & r & i \\ c & t & i & r \\ \end{bmatrix}\end{split}\]

Parameters:

• t (complex | ndarray) – Transmission coefficient. For multimode ports, a sequence of coefficients must be provided.

• c (complex | ndarray) – Coupling coefficient. For multimode ports, a sequence of coefficients must be provided.

• i (complex | ndarray) – Isolation coefficient. For multimode ports, a sequence of coefficients must be provided.

• r (complex | ndarray) – Reflection coefficient. For multimode ports, a sequence of coefficients must be provided.

• ports (Sequence[str] | None) – List of port names. If not set, the sorted list of port names from the component is used.

Notes

For multimode ports, mixed-mode coefficients are zero (not included in the result). Dispersion can be included in the model by setting the coefficients to a 2D array with shape (M, N), in which M is the number of modes, and N the length of the frequency sequence used in the S matrix computation.

Methods

from_bytes(byte_repr)	De-serialize this model.
s_matrix(component, frequencies[, ...])	Compute the S matrix for a component using this model.
start(component, frequencies, **kwargs)	Start computing the S matrix response from a component.
update(*args, **kwargs)	Update this model.

Attributes

as_bytes	Serialize this model.
parametric_function	Function used to update a parametric component.
parametric_kwargs	Keyword arguments used to update a parametric component.
properties	Object properties.
random_variables	Random variables associated to this modles's parameters.

property as_bytes: bytes

Serialize this model.

classmethod from_bytes(byte_repr)

De-serialize this model.

Parameters:

byte_repr (bytes)

Return type:

DirectionalCouplerModel

start(component, frequencies, **kwargs)

Start computing the S matrix response from a component.

Parameters:

• component (Component) – Component from which to compute the S matrix.

• frequencies (Sequence[float]) – Sequence of frequencies at which to perform the computation.

• **kwargs (Any) – Unused.

Returns:

Model result with attributes status and s_matrix.

Return type:

ModelResult