FiberPort

FiberPort(
    center,
    input_vector,
    size,
    extrusion_limits,
    cross_section=(),
    num_modes=1,
    polarization=None,
    target_neff=None,
    added_solver_modes=0,
)

Fiber beam port.

This 3D port models an optical fiber or any type of waveguide extruded from a 2D cross-section.

Args

• center (Sequence[float]): Port position in 3D.
• input_vector (Sequence[float]): 3D input vector (beam propagation direction).
• size (Sequence[float] | complex): 2D cross-section size for mode solver.
• extrusion_limits (Sequence[float]): Cross-section extrusion limits when generating the 3D structures the make the port waveguide, in the form (lower, upper). The lower limit must be negative and defines how far behind the port plane (w.r.t. the input vector) the structures extend. The upper limit must be positive and defines how far along the input vector direction the structures are extruded.
• cross_section (Sequence[tuple[Rectangle | Circle | Polygon | Path, MediumType]]): Sequence of 2D structure and a medium tuples defining the fiber cross-section.
• num_modes (int): Number of modes supported by this port.
• polarization (Literal["", “TE”, “TM”] | None): Mode polarization selection.
• target_neff (float | None): Target effective index for numerical mode solving. If None, the square root of the largest real permittivity among the cross-section and background media at the mode solving frequencies is used.
• added_solver_modes (int): Additional modes to solve for in mode solver runs (useful when filtering modes by polarization). These are not included in S paramters computed for ports if this type.

Note

The cross section is centered around (0, 0). Extruded structures are translated to the port center after extrusion.

Extrusion limits must be non-zero in both directions to guarantee that the cross-section intersects the inside of the extruded geometries.

Example

>>> # Slightly elliptical core to break mode degeneracy
>>> core = pf.Circle((2.01, 2))
>>> fiber_port = pf.FiberPort(
...     (-10, 50, 1),
...     (1, 0, 0),
...     (10, 10),
...     (-100, 0.1),
...     cross_section=[(core, td.Medium(permittivity=1.46**2))],
...     num_modes=2,
...     target_neff=2,
... )
>>> mode_solver = fiber_port.to_tidy3d_mode_solver(
...     [pf.C_0 / 1.55], technology=pf.basic_technology()
... )
>>> ms_data = mode_solver.solve()  # doctest: +SKIP
>>> ms_data.to_dataframe()  # doctest: +SKIP

See Also

Fiber ports guide

Methods

Method	Description
copy	Create a copy of this port.
is_connected_to	Check if this port is connected to another one.
matches	Check if this port matches another one.
reflected	Create a reflected version of this port.
to_tidy3d_mode_solver	Create a Tidy3D ModeSolver from this port.
to_tidy3d_monitor	Create a Tidy3D ModeMonitor from this port.
to_tidy3d_source	Create a Tidy3D ModeSource from this port.
to_tidy3d_structures	Create Tidy3D structures by extruding this port.

copy

copy(self, deep=False)

Create a copy of this port.

Args

• deep (bool): If set, creates a deep copy.

Returns

FiberPort: New copy.

is_connected_to

is_connected_to(self, port)

Check if this port is connected to another one.

Two ports are connected when they are placed in the same location, have opposite input directions and compatible modes.

Args

• port (Port | FiberPort | GaussianPort): Port against which to check.

Returns

bool: Boolean indicating if the ports are connected.

matches

matches(self, port)

Check if this port matches another one.

Args

• port (Port | FiberPort | GaussianPort): Port against which to check.

Returns

bool: Boolean indicating if the ports match.

reflected

reflected(self)

Create a reflected version of this port.

The new port points the opposite direction of the original port and has the opposite beam mode.

Returns

FiberPort: Reflected Fiber port.

to_tidy3d_mode_solver

to_tidy3d_mode_solver(
    self,
    frequencies,
    mesh_refinement=None,
    group_index=False,
    technology=None,
    use_angle_rotation=False,
)

Create a Tidy3D ModeSolver from this port.

Args

• frequencies (Sequence[float]): Frequencies for the mode solver.
• mesh_refinement (float | None): Minimal number of mesh elements per wavelength used for mode solving.
• group_index (bool): Boolean indicating whether the mode solver should include group index computation.
• technology (Technology | None): Technology specification for this port.
• use_angle_rotation (bool): Enable the use of angle_rotation in the ModeSpec used by the mode solver.

Returns

ModeSolver: Tidy3D mode solver.

to_tidy3d_monitor

to_tidy3d_monitor(
    self, frequencies, name, use_angle_rotation=False, technology=None
)

Create a Tidy3D ModeMonitor from this port.

Args

• frequencies (Sequence[float]): Frequencies for the mode monitor.
• name (str): Name for the created monitor.
• use_angle_rotation (bool): Enable the use of angle_rotation in the ModeSpec used by the monitor.
• technology (Technology | None): Technology specification used for the default target_neff.

Returns

tidy3d.ModeMonitor: Tidy3D mode monitor.

to_tidy3d_source

to_tidy3d_source(
    self,
    frequencies,
    mode_index=0,
    name=None,
    use_angle_rotation=False,
    technology=None,
)

Create a Tidy3D ModeSource from this port.

Args

• frequencies (Sequence[float]): Frequencies for the mode source.
• mode_index (int): Mode index to be used as source (must be less than the number of modes supported by this port).
• name (str | None): Optional name for the created source.
• use_angle_rotation (bool): Enable the use of angle_rotation in the ModeSpec used by the source.
• technology (Technology | None): Technology specification used for the default target_neff.

Returns

tidy3d.ModeSource: Tidy3D mode source.

to_tidy3d_structures

to_tidy3d_structures(self)

Create Tidy3D structures by extruding this port.

Returns

list[tidy3d.Structure]: Tidy3D structures from the cross-section.

Attributes

Attribute	Description
added_solver_modes	int: Additinal modes to include in mode solver runs for this port.
center	ndarray: Fiber port center.
classification	Literal[“optical”, “electrical”]: Port classification: optical or electrical (read only).
cross_section	list[tuple[Rectangle | Circle | Polygon | Path, MediumType]]: Fiber port cross-section structures and media.
extrusion_limits	ndarray: Fiber port extrusion limits.
input_vector	ndarray: Fiber port input direction.
num_modes	int: Number of modes supported by this port.
polarization	Literal["", “TE”, “TM”]: Mode polarization selection.
properties	Properties: Object properties.
size	ndarray: Fiber port cross-section size.
target_neff	float | None: Target effective index for port modes (None for the default).

added_solver_modes

int: Additinal modes to include in mode solver runs for this port.

center

ndarray: Fiber port center.

classification

Literal[“optical”, “electrical”]: Port classification: optical or electrical (read only).

cross_section

list[tuple[Rectangle | Circle | Polygon | Path, MediumType]]: Fiber port cross-section structures and media.

extrusion_limits

ndarray: Fiber port extrusion limits.

input_vector

ndarray: Fiber port input direction.

num_modes

int: Number of modes supported by this port.

polarization

Literal["", “TE”, “TM”]: Mode polarization selection.

properties

Properties: Object properties.

size

ndarray: Fiber port cross-section size.

target_neff

float | None: Target effective index for port modes (None for the default).