WaveguideModel

class photonforge.WaveguideModel(n_complex=None, length=None, mesh_refinement=None, verbose=True)

Data model for straight waveguides.

The component is expected to have 2 ports with identical profiles. The S matrix is zero for all reflection or mixed-mode coefficients. Same-mode transmission coefficients are modeled by:

\[S_{jk} = \exp(i 2 \pi f n_c L / c₀)\]

with \(n_c\) the complex effective index for the port profile modes, and \(L\) the waveguide length.

Parameters:

• n_complex (complex | Sequence[complex] | Sequence[Sequence[complex]] | PortSpec | Literal['cross-section'] | None) – Waveguide complex effective index. For multimode models, a sequence of indices must be provided, one for each mode. If set to None, automatic computation is performed by mode-solving the first component port. If desired, the port specification of the component port can be overridden by setting n_complex to "cross-section" (uses Component.slice_profile()) or to a PortSpec object.

• length (Annotated[float, units='μm'] | None) – Physical length of the waveguide. If not provided, the length is measured by route_length() or ports distance.

• mesh_refinement (Annotated[float, exclusiveMinimum=0] | None) – Minimal number of mesh elements per wavelength used for mode solving.

• verbose (bool) – Flag setting the verbosity of mode solver runs.

Note

Dispersion can be included in the model by setting n_complex to a 2D array with shape (M, N), in which M is the number of modes in the waveguide, and N the length of the frequency sequence used in the S matrix computation.

See also

Mach-Zehnder Interferometer

Methods

black_box_component([port_spec, technology, ...])	Create a black-box component using this model for testing.
estimate_cost(*args, **kwargs)	Estimate the cost for S matrix computation.
from_bytes(byte_repr)	De-serialize this model.
s_matrix(component, frequencies[, ...])	Compute the S matrix for a component using this model.
setup_time_stepper(component, time_step[, ...])	Obtain a time stepper for a component using this model.
start(component, frequencies[, verbose, ...])	Start computing the S matrix response from a component.
update(*args, **kwargs)	Update this model.

Attributes

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.
time_stepper	Time stepper associated with this model.

black_box_component(port_spec=None, technology=None, name=None)

Create a black-box component using this model for testing.

Parameters:

• port_spec (str | PortSpec | None) – Port specification used in the component. If None, look for "port_spec" in config.default_kwargs.

• technology (Technology | None) – Component technology. If None, the default technology is used.

• name (str | None) – Component name. If None a default is used.

Returns:

Component with ports and model.

Return type:

Component

classmethod from_bytes(byte_repr)

De-serialize this model.

Parameters:

byte_repr (bytes)

Return type:

WaveguideModel

start(component, frequencies, verbose=None, cost_estimation=False, **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.

• verbose (bool | None) – If set, overrides the model’s verbose attribute.

• cost_estimation (bool) – If set, simulations are uploaded, but not executed. S matrix may not be computed.

• **kwargs (Any) – Unused.

Returns:

Result object with attributes status and s_matrix.

Return type:

SMatrix | _WaveguideModelRunner