ExtrusionSpec¶

class photonforge.ExtrusionSpec(mask_spec, medium, limits, sidewall_angle=0, reference='top')¶

Extrusion specification for masks.

This class is mainly used to create extrusion recipes for a Technology.

Parameters:

mask_spec (MaskSpec) – Mask specification for this extrusion.
medium (MediumType | dict[Literal["optical", "electrical"], MediumType]) – Tidy3D medium for the resulting structures. Different media can be used for optical and electrical frequencies by using a dictionary (see note below).
limits (Sequence[float]) – Out-of-plane extrusion limits.
sidewall_angle (float) – Sidewall angle for extrusion (in degrees). Positive values will dilate the bottom face or erode the top face, according to the reference position.
reference (Literal["top", "bottom", "middle"] | float) – Reference position for computing dilations and erosions when using a sidewall angle.

Example

>>> extrusion_spec = ExtrusionSpec(
...     MaskSpec((1, 0)),
...     td.Medium(permittivity=3.48**2),
...     limits=(0, 0.250),
...     sidewall_angle=8,
... )

Note

The medium used for simulations in optical and electrical frequency ranges (see frequency_classification()) can be set individually with:

>>> media = {
...     "optical": td.Medium(permittivity=3.48**2),
...     "electrical": td.Medium(permittivity=12.3),
... }
>>> extrusion_spec = ExtrusionSpec(
...     MaskSpec((1, 0)),
...     medium=media,
...     limits=(0, 0.250),
...     sidewall_angle=8,
... )

Methods

`copy`([deep])	Create a copy of this extrusion specification.
`extrude`(*structures[, extrusion_tolerance, ...])	Extrude planar structures according to this extrusion specification.
`from_json`(json_str)	Import object data from json.
`get_medium`(classification)	Return electrical or optical medium for this extrusion specification.

Attributes

`json`	(DEPRECATED) Json representation of this layer specification.
`limits`	Extrusion limits.
`mask_spec`	Extrusion mask specification.
`medium`	Extrusion medium.
`properties`	Object properties.
`reference`	Extrusion reference position.
`sidewall_angle`	Extrusion sidewall_angle (in degrees).

copy(deep=False)¶

Create a copy of this extrusion specification.

Parameters:: deep (bool) – If set, creates a copy of mask specification as well. Otherwise, the same mask specification object will be used.
Returns:: New copy.
Return type:: ExtrusionSpec

extrude(*structures, extrusion_tolerance=0, classification='optical')¶

Extrude planar structures according to this extrusion specification.

Parameters:

*structures (Rectangle | Circle | Polygon | Path) – Structures to be extruded.
extrusion_tolerance (float) – Minimal dimension to search for topological changes in angled extrusions or fallback to an orthogonal profile. A value of 0 or less defaults to config.tolerance.
classsification (Literal["optical", "electrical"]) – Frequency classification indicating which type of medium to use.

Returns:

List of 3D structures.

Return type:

list[Polyhedron | Extruded | ConstructiveSolid]

Note

The mask specification in this object is not taken into account. All structures are used in the extrusion and no dilation is applied.

static from_json(json_str)¶

Import object data from json.

Warning

This method is DEPRECATED and will be removed in the next release.

Parameters:: json_str (str) – String containing the json data.
Returns:: PhotonForge object.
Return type:: Any

get_medium(classification)¶

Return electrical or optical medium for this extrusion specification.

Parameters:: classification (Literal["optical", "electrical"]) – Frequency classification of the desired medium.
Returns:: Medium for the chosen classification.
Return type:: MediumType