"""Rectangular dielectric waveguide utilities."""
from typing import List, Any
import numpy
import pydantic.v1 as pydantic
from ...components.base import Tidy3dBaseModel, cached_property, skip_if_fields_missing
from ...components.boundary import BoundarySpec, Periodic
from ...components.data.data_array import ModeIndexDataArray, FreqModeDataArray
from ...components.geometry.base import Box
from ...components.geometry.polyslab import PolySlab
from ...components.grid.grid_spec import GridSpec
from ...components.medium import Medium, MediumType
from ...components.mode import ModeSpec
from ...components.simulation import Simulation
from ...components.source import ModeSource, GaussianPulse
from ...components.structure import Structure
from ...components.types import ArrayFloat1D, Ax, Axis, Coordinate, Literal, Size1D, Union
from ...components.types import TYPE_TAG_STR
from ...constants import C_0, inf, MICROMETER, RADIAN
from ...exceptions import Tidy3dError, ValidationError
from ...log import log
from ..mode.mode_solver import ModeSolver
[docs]class RectangularDielectric(Tidy3dBaseModel):
"""General rectangular dielectric waveguide
Supports:
- Strip and rib geometries
- Angled sidewalls
- Modes in waveguide bends
- Surface and sidewall loss models
- Coupled waveguides
"""
wavelength: Union[float, ArrayFloat1D] = pydantic.Field(
...,
title="Wavelength",
description="Wavelength(s) at which to calculate modes (in μm).",
units=MICROMETER,
)
core_width: Union[Size1D, ArrayFloat1D] = pydantic.Field(
...,
title="Core width",
description="Core width at the top of the waveguide. If set to an array, defines "
"the widths of adjacent waveguides.",
units=MICROMETER,
)
core_thickness: Size1D = pydantic.Field(
...,
title="Core Thickness",
description="Thickness of the core layer.",
units=MICROMETER,
)
core_medium: MediumType = pydantic.Field(
...,
title="Core Medium",
description="Medium associated with the core layer.",
discriminator=TYPE_TAG_STR,
)
clad_medium: MediumType = pydantic.Field(
...,
title="Clad Medium",
description="Medium associated with the upper cladding layer.",
discriminator=TYPE_TAG_STR,
)
box_medium: MediumType = pydantic.Field(
None,
title="Box Medium",
description="Medium associated with the lower cladding layer.",
discriminator=TYPE_TAG_STR,
)
slab_thickness: Size1D = pydantic.Field(
0.0,
title="Slab Thickness",
description="Thickness of the slab for rib geometry.",
units=MICROMETER,
)
clad_thickness: Size1D = pydantic.Field(
None,
title="Clad Thickness",
description="Domain size above the core layer.",
units=MICROMETER,
)
box_thickness: Size1D = pydantic.Field(
None,
title="Box Thickness",
description="Domain size below the core layer.",
units=MICROMETER,
)
side_margin: Size1D = pydantic.Field(
None,
title="Side Margin",
description="Domain size to the sides of the waveguide core.",
units=MICROMETER,
)
sidewall_angle: float = pydantic.Field(
0.0,
title="Sidewall Angle",
description="Angle of the core sidewalls measured from the vertical direction (in "
"radians). Positive (negative) values create waveguides with bases wider (narrower) "
"than their tops.",
units=RADIAN,
)
gap: Union[float, ArrayFloat1D] = pydantic.Field(
0.0,
title="Gap",
description="Distance between adjacent waveguides, measured at the top core edges. "
"An array can be used to define one gap per pair of adjacent waveguides.",
units=MICROMETER,
)
sidewall_thickness: Size1D = pydantic.Field(
0.0,
title="Sidewall Thickness",
description="Sidewall layer thickness (within core).",
units=MICROMETER,
)
sidewall_medium: MediumType = pydantic.Field(
None,
title="Sidewall medium",
description="Medium associated with the sidewall layer to model sidewall losses.",
discriminator=TYPE_TAG_STR,
)
surface_thickness: Size1D = pydantic.Field(
0.0,
title="Surface Thickness",
description="Thickness of the surface layers defined on the top of the waveguide and "
"slab regions (if any).",
units=MICROMETER,
)
surface_medium: MediumType = pydantic.Field(
None,
title="Surface Medium",
description="Medium associated with the surface layer to model surface losses.",
discriminator=TYPE_TAG_STR,
)
origin: Coordinate = pydantic.Field(
(0, 0, 0),
title="Origin",
description="Center of the waveguide geometry. This coordinate represents the base "
"of the waveguides (substrate surface) in the normal axis, and center of the geometry "
"in the remaining axes.",
units=MICROMETER,
)
length: Size1D = pydantic.Field(
1e30,
title="Length",
description="Length of the waveguides in the propagation direction",
units=MICROMETER,
)
propagation_axis: Axis = pydantic.Field(
0,
title="Propagation Axis",
description="Axis of propagation of the waveguide",
)
normal_axis: Axis = pydantic.Field(
2,
title="Normal Axis",
description="Axis normal to the substrate surface",
)
mode_spec: ModeSpec = pydantic.Field(
ModeSpec(num_modes=2),
title="Mode Specification",
description=":class:`ModeSpec` defining waveguide mode properties.",
)
grid_resolution: int = pydantic.Field(
15,
title="Grid Resolution",
description="Solver grid resolution per wavelength.",
)
max_grid_scaling: float = pydantic.Field(
1.2,
title="Maximal Grid Scaling",
description="Maximal size increase between adjacent grid boundaries.",
)
@pydantic.validator("wavelength", "core_width", "gap", always=True)
def _set_array(cls, val):
"""Ensure values are not negative and convert to numpy arrays."""
result = numpy.array(val, ndmin=1)
if any(result < 0):
raise ValidationError("Values may not be negative.")
return result
@pydantic.validator("box_medium", always=True)
@skip_if_fields_missing(["clad_medium"])
def _set_box_medium(cls, val, values):
"""Set BOX medium same as cladding as default value."""
return values["clad_medium"] if val is None else val
@pydantic.validator("clad_thickness", always=True)
@skip_if_fields_missing(["clad_medium", "wavelength"])
def _set_clad_thickness(cls, val, values):
"""Set default cladding thickness based on the max wavelength in the cladding medium."""
if val is None:
wavelength = values["wavelength"]
medium = values["clad_medium"]
n = numpy.array([medium.nk_model(f)[0] for f in C_0 / wavelength])
lda = wavelength / n
return 1.5 * lda.max()
return val
@pydantic.validator("box_thickness", always=True)
@skip_if_fields_missing(["clad_medium", "wavelength"])
def _set_box_thickness(cls, val, values):
"""Set default BOX thickness based on the max wavelength in the BOX medium."""
if val is None:
wavelength = values["wavelength"]
medium = values["box_medium"]
n = numpy.array([medium.nk_model(f)[0] for f in C_0 / wavelength])
lda = wavelength / n
return 1.5 * lda.max()
return val
@pydantic.validator("side_margin", always=True)
@skip_if_fields_missing(["clad_thickness", "box_thickness"])
def _set_side_margin(cls, val, values):
"""Set default side margin based on BOX and cladding thicknesses."""
return max(values["clad_thickness"], values["box_thickness"]) if val is None else val
@pydantic.validator("gap", always=True)
@skip_if_fields_missing(["core_width"])
def _validate_gaps(cls, val, values):
"""Ensure the number of gaps is compatible with the number of cores supplied."""
if val.size == 1 and values["core_width"].size != 2:
# If a single value is defined, use it for all gaps
return numpy.array([val[0]] * (values["core_width"].size - 1))
if val.size != values["core_width"].size - 1:
raise ValidationError("Number of gaps must be 1 less than number of core widths.")
return val
@pydantic.root_validator
def _ensure_consistency(cls, values):
"""Ensure consistency in setting surface/sidewall models and propagation/normal axes."""
sidewall_thickness = values["sidewall_thickness"]
sidewall_medium = values["sidewall_medium"]
surface_thickness = values["surface_thickness"]
surface_medium = values["surface_medium"]
propagation_axis = values["propagation_axis"]
normal_axis = values["normal_axis"]
if sidewall_thickness > 0 and sidewall_medium is None:
raise ValidationError(
"Sidewall medium must be provided when sidewall thickness is greater than 0."
)
if sidewall_thickness == 0 and sidewall_medium is not None:
log.warning("Sidewall medium not used because sidewall thickness is zero.")
if surface_thickness > 0 and surface_medium is None:
raise ValidationError(
"Surface medium must be provided when surface thickness is greater than 0."
)
if surface_thickness == 0 and surface_medium is not None:
log.warning("Surface medium not used because surface thickness is zero.")
if propagation_axis == normal_axis:
raise ValidationError("Propagation and normal axes must be different.")
return values
@cached_property
def lateral_axis(self) -> Axis:
"""Lateral direction axis."""
return 3 - self.propagation_axis - self.normal_axis
def _swap_axis(
self, lateral_coord: Any, normal_coord: Any, propagation_coord: Any
) -> List[Any]:
"""Swap the model coordinates to desired axes."""
result = [None, None, None]
result[self.lateral_axis] = lateral_coord
result[self.propagation_axis] = propagation_coord
result[self.normal_axis] = normal_coord
return result
def _translate(
self, lateral_coord: float, normal_coord: float, propagation_coord: float
) -> List[float]:
"""Swap the model coordinates to desired axes and translate to origin."""
coordinates = self._swap_axis(lateral_coord, normal_coord, propagation_coord)
result = [a + b for a, b in zip(self.origin, coordinates)]
return result
def _transform_in_plane(self, lateral_coord: float, propagation_coord: float) -> List[float]:
"""Swap the model coordinates to desired axes in the substrate plane."""
result = self._translate(lateral_coord, 0, propagation_coord)
_, result = Box.pop_axis(result, self.normal_axis)
return result
@cached_property
def height(self) -> Size1D:
"""Domain height (size in the normal direction)."""
return self.box_thickness + self.core_thickness + self.clad_thickness
@cached_property
def width(self) -> Size1D:
"""Domain width (size in the lateral direction)."""
w = self.core_width.sum() + self.gap.sum() + 2 * self.side_margin
if self.sidewall_angle > 0:
w += 2 * self.core_thickness * numpy.tan(self.sidewall_angle)
return w
@property
def _core_starts(self) -> List[float]:
"""Starting positions of each waveguide (x is the position in the lateral direction)."""
core_x = [-0.5 * (self.core_width.sum() + self.gap.sum())]
core_x.extend(core_x[0] + numpy.cumsum(self.core_width[:-1]) + numpy.cumsum(self.gap))
return core_x
@property
def _override_structures(self) -> List[Structure]:
"""Build override structures to define the simulation grid."""
# Grid resolution factor applied to the materials (increase for waveguide corners
# and decrease for evanescent tail regions).
scale_factor = 1.5
freqs = C_0 / self.wavelength
nk_core = numpy.array([self.core_medium.nk_model(f) for f in freqs])
nk_clad = numpy.array([self.clad_medium.nk_model(f) for f in freqs])
nk_box = numpy.array([self.box_medium.nk_model(f) for f in freqs])
lda_core = self.wavelength / nk_core[:, 0]
lda_clad = self.wavelength / nk_clad[:, 0]
lda_box = self.wavelength / nk_box[:, 0]
core_x = self._core_starts
i = numpy.argmin(lda_core)
hi_index = Medium.from_nk(n=nk_core[i, 0] * scale_factor, k=0, freq=freqs[i])
i = numpy.argmin(lda_box)
lo_index_box = Medium.from_nk(n=max(1.0, nk_box[i, 0] / scale_factor), k=0, freq=freqs[i])
i = numpy.argmin(lda_clad)
lo_index_clad = Medium.from_nk(n=max(1.0, nk_clad[i, 0] / scale_factor), k=0, freq=freqs[i])
# Gather all waveguide edge intervals into `hi_res` list
corner_margin = max(lda_box.max(), lda_clad.max()) / self.grid_resolution
if self.sidewall_angle > 0:
dx = (self.core_thickness - self.slab_thickness) * numpy.tan(self.sidewall_angle)
hi_res = [
pair
for x, w in zip(core_x, self.core_width)
for pair in [
[x - dx - corner_margin, x + corner_margin],
[x + w - corner_margin, x + w + dx + corner_margin],
]
]
elif self.sidewall_angle < 0:
dx = (self.core_thickness - self.slab_thickness) * numpy.tan(self.sidewall_angle)
hi_res = [
pair
for x, w in zip(core_x, self.core_width)
for pair in [
[x - corner_margin, x - dx + corner_margin],
[x + w + dx - corner_margin, x + w + corner_margin],
]
]
else:
hi_res = [
pair
for x, w in zip(core_x, self.core_width)
for pair in [
[x - corner_margin, x + corner_margin],
[x + w - corner_margin, x + w + corner_margin],
]
]
# The gaps between waveguides can be small enough to merge adjacent high
# resolution intervals (specially with angled sidewalls), so we merge
# intervals that overlap
i = 0
while i < len(hi_res) - 1:
if hi_res[i][1] >= hi_res[i + 1][0]:
hi_res[i][1] = hi_res.pop(i + 1)[1]
else:
i += 1
# Create override structures to improve the mode solver grid. We want
# high resolution around all core edges, but not along the whole slab
# in case of rib geometry. Start with the 4 corners:
override_structures = [
Structure(
geometry=Box(
center=self._translate(0.5 * (a + b), y, 0),
size=self._swap_axis(b - a, 2 * corner_margin, inf),
),
medium=hi_index,
)
for (a, b) in hi_res
for y in (self.slab_thickness, self.core_thickness)
]
# Low resolution on the sides:
override_structures.extend(
Structure(
geometry=Box(
center=self._translate(0.5 * (a + b), 0, 0),
size=self._swap_axis(b - a, inf, inf),
),
medium=lo_index_clad,
)
for (a, b) in ((-self.width, hi_res[0][0]), (hi_res[-1][1], self.width))
)
# Low resolution above and below:
override_structures.extend(
Structure(
geometry=Box(
center=self._translate(0, 0.5 * (a + b), 0),
size=self._swap_axis(inf, b - a, inf),
),
medium=lo_index,
)
for (a, b, lo_index) in (
(-2 * self.box_thickness, -corner_margin, lo_index_box),
(
self.core_thickness + corner_margin,
self.core_thickness + 2 * self.clad_thickness,
lo_index_clad,
),
)
)
return override_structures
@cached_property
def grid_spec(self) -> GridSpec:
"""Waveguide grid specification with overriding geometry."""
grid_spec = GridSpec.auto(
min_steps_per_wvl=self.grid_resolution,
wavelength=self.wavelength.min(),
override_structures=self._override_structures,
max_scale=self.max_grid_scaling,
)
return grid_spec
@cached_property
def structures(self) -> List[Structure]:
"""Waveguide structures for simulation, including the core(s), slabs (if any), and bottom
cladding, if different from the top. For bend modes, the structure is a 270 degree bend
regardless of :attr:`length`."""
# Create a local copy of these values, as they will be modified
# according to the desired geometry
core_w = numpy.array(self.core_width, copy=True)
core_t = self.core_thickness
slab_t = self.slab_thickness
core_x = self._core_starts
if self.mode_spec.bend_radius is None or self.mode_spec.bend_radius == 0.0:
half_length = 0.5 * self.length
def polyslab_vertices(x, w):
return (
self._transform_in_plane(x, -half_length),
self._transform_in_plane(x + w, -half_length),
self._transform_in_plane(x + w, half_length),
self._transform_in_plane(x, half_length),
)
else:
if (self.normal_axis > self.lateral_axis) != (self.mode_spec.bend_axis == 1):
raise Tidy3dError(
"Waveguide band axis must be the substrate normal "
f"(mode_spec.bend_axis = {1 - self.mode_spec.bend_axis})"
)
bend_radius = self.mode_spec.bend_radius
# 10 nm resolution (at center)
num_points = 1 + int(0.5 + 1.5 * numpy.pi * abs(bend_radius) / 0.01)
angles = numpy.linspace(-0.75 * numpy.pi, 0.75 * numpy.pi, num_points)
if bend_radius < 0:
angles = -angles
sin = numpy.sin(angles)
cos = numpy.cos(angles)
def polyslab_vertices(x, w):
r_in = bend_radius + x
v_in = numpy.vstack((-bend_radius + r_in * cos, r_in * sin)).T
r_out = r_in + w
v_out = numpy.vstack((-bend_radius + r_out * cos, r_out * sin)).T
return [self._transform_in_plane(*v) for v in list(v_out) + list(v_in[::-1])]
# Create the actual waveguide geometry
structures = []
normal_origin = self.origin[self.normal_axis]
# Surface and sidewall loss regions are created first, so that the core
# can be applied on top.
if self.surface_thickness > 0:
structures.extend(
Structure(
geometry=PolySlab(
vertices=polyslab_vertices(x, w),
slab_bounds=(
normal_origin + core_t - self.surface_thickness,
normal_origin + core_t,
),
sidewall_angle=self.sidewall_angle,
reference_plane="top",
axis=self.normal_axis,
),
medium=self.surface_medium,
)
for x, w in zip(core_x, core_w)
)
# Add loss region over slab surface, if rib geometry
if slab_t > 0:
structures.append(
Structure(
geometry=Box(
center=self._translate(0, 0.5 * slab_t, 0),
size=self._swap_axis(inf, slab_t, self.length),
),
medium=self.surface_medium,
)
)
# Correct core geometry to leave the lossy regions with their
# specified thickness
dx = self.surface_thickness * numpy.tan(self.sidewall_angle)
core_x -= dx
core_w += 2 * dx
core_t -= self.surface_thickness
slab_t = max(0, slab_t - self.surface_thickness)
if self.sidewall_thickness > 0:
structures.extend(
Structure(
geometry=PolySlab(
vertices=polyslab_vertices(x, w),
slab_bounds=(normal_origin, normal_origin + core_t),
sidewall_angle=self.sidewall_angle,
reference_plane="top",
axis=self.normal_axis,
),
medium=self.sidewall_medium,
)
for x, w in zip(core_x, core_w)
)
# Core position offset and width reduction to accommodate lossy
# regions
dx = self.sidewall_thickness / numpy.cos(self.sidewall_angle)
core_x += dx
core_w -= 2 * dx
# Waveguide cores
structures.extend(
Structure(
geometry=PolySlab(
vertices=polyslab_vertices(x, w),
slab_bounds=(normal_origin, normal_origin + core_t),
sidewall_angle=self.sidewall_angle,
reference_plane="top",
axis=self.normal_axis,
),
medium=self.core_medium,
)
for x, w in zip(core_x, core_w)
)
# Slab for rib geometry
if slab_t > 0:
structures.append(
Structure(
geometry=Box(
center=self._translate(0, 0.5 * slab_t, 0),
size=self._swap_axis(inf, slab_t, self.length),
),
medium=self.core_medium,
)
)
# Lower cladding
if self.box_medium != self.clad_medium:
structures.append(
Structure(
geometry=Box(
center=self._translate(0, -self.box_thickness, 0),
size=self._swap_axis(inf, 2 * self.box_thickness, self.length),
),
medium=self.box_medium,
)
)
return structures
@cached_property
def mode_solver(self) -> ModeSolver:
"""Create a mode solver based on this waveguide structure
Returns
-------
:class:`ModeSolver`
Example
-------
>>> wg = waveguide.RectangularDielectric(
... wavelength=1.55,
... core_width=0.5,
... core_thickness=0.22,
... core_medium=Medium(permittivity=3.48**2),
... clad_medium=Medium(permittivity=1.45**2),
... num_modes=2,
... )
>>> mode_data = wg.mode_solver.solve()
>>> mode_data.n_eff.values
array([[2.4536054 1.7850305]], dtype=float32)
"""
freqs = C_0 / self.wavelength
f_max = freqs.max()
f_min = freqs.min()
freq0 = 0.5 * (f_max + f_min)
fwidth = max(0.1 * freq0, f_max - f_min)
plane = Box(
center=self._translate(0, 0.5 * self.height - self.box_thickness, 0),
size=self._swap_axis(self.width, self.height, 0),
)
# Source used only to silence warnings
mode_source = ModeSource(
center=plane.center,
size=plane.size,
source_time=GaussianPulse(freq0=freq0, fwidth=fwidth),
direction="+",
mode_spec=self.mode_spec,
)
simulation = Simulation(
center=plane.center,
size=plane.size,
medium=self.clad_medium,
structures=self.structures,
boundary_spec=BoundarySpec.all_sides(Periodic()),
grid_spec=self.grid_spec,
sources=[mode_source],
run_time=1e-12,
)
mode_solver = ModeSolver(
simulation=simulation,
plane=plane,
mode_spec=self.mode_spec,
freqs=freqs,
)
return mode_solver
@property
def n_eff(self) -> ModeIndexDataArray:
"""Calculate the effective index."""
return self.mode_solver.data.n_eff
@property
def n_complex(self) -> ModeIndexDataArray:
"""Calculate the complex effective index."""
return self.mode_solver.data.n_complex
@property
def n_group(self) -> ModeIndexDataArray:
r"""Calculate the group index."""
return self.mode_solver.data.n_group
@property
def mode_area(self) -> FreqModeDataArray:
"""Calculate the effective mode area."""
return self.mode_solver.data.mode_area
# plot wrappers
[docs] def plot(
self,
x: float = None,
y: float = None,
z: float = None,
ax: Ax = None,
source_alpha: float = None,
monitor_alpha: float = None,
**patch_kwargs,
) -> Ax:
"""Plot each of simulation's components on a plane defined by one nonzero x,y,z coordinate.
Parameters
----------
x : float = None
position of plane in x direction, only one of x, y, z must be specified to define plane.
y : float = None
position of plane in y direction, only one of x, y, z must be specified to define plane.
z : float = None
position of plane in z direction, only one of x, y, z must be specified to define plane.
source_alpha : float = None
Opacity of the sources. If ``None``, uses Tidy3d default.
monitor_alpha : float = None
Opacity of the monitors. If ``None``, uses Tidy3d default.
ax : matplotlib.axes._subplots.Axes = None
Matplotlib axes to plot on, if not specified, one is created.
Returns
-------
matplotlib.axes._subplots.Axes
The supplied or created matplotlib axes.
"""
return self.mode_solver.simulation.plot(
x=x,
y=y,
z=z,
ax=ax,
source_alpha=source_alpha,
monitor_alpha=monitor_alpha,
**patch_kwargs,
)
[docs] def plot_eps(
self,
x: float = None,
y: float = None,
z: float = None,
freq: float = None,
alpha: float = None,
source_alpha: float = None,
monitor_alpha: float = None,
ax: Ax = None,
) -> Ax:
"""Plot each of simulation's components on a plane defined by one nonzero x,y,z coordinate.
The permittivity is plotted in grayscale based on its value at the specified frequency.
Parameters
----------
x : float = None
position of plane in x direction, only one of x, y, z must be specified to define plane.
y : float = None
position of plane in y direction, only one of x, y, z must be specified to define plane.
z : float = None
position of plane in z direction, only one of x, y, z must be specified to define plane.
freq : float = None
Frequency to evaluate the relative permittivity of all mediums.
If not specified, evaluates at infinite frequency.
alpha : float = None
Opacity of the structures being plotted.
Defaults to the structure default alpha.
source_alpha : float = None
Opacity of the sources. If ``None``, uses Tidy3d default.
monitor_alpha : float = None
Opacity of the monitors. If ``None``, uses Tidy3d default.
ax : matplotlib.axes._subplots.Axes = None
Matplotlib axes to plot on, if not specified, one is created.
Returns
-------
matplotlib.axes._subplots.Axes
The supplied or created matplotlib axes.
"""
return self.mode_solver.simulation.plot_eps(
x=x,
y=y,
z=z,
freq=freq,
alpha=alpha,
source_alpha=source_alpha,
monitor_alpha=monitor_alpha,
ax=ax,
)
[docs] def plot_structures(
self, x: float = None, y: float = None, z: float = None, ax: Ax = None
) -> Ax:
"""Plot each of simulation's structures on a plane defined by one nonzero x,y,z coordinate.
Parameters
----------
x : float = None
position of plane in x direction, only one of x, y, z must be specified to define plane.
y : float = None
position of plane in y direction, only one of x, y, z must be specified to define plane.
z : float = None
position of plane in z direction, only one of x, y, z must be specified to define plane.
ax : matplotlib.axes._subplots.Axes = None
Matplotlib axes to plot on, if not specified, one is created.
Returns
-------
matplotlib.axes._subplots.Axes
The supplied or created matplotlib axes.
"""
return self.mode_solver.simulation.plot_structures(
x=x,
y=y,
z=z,
ax=ax,
)
[docs] def plot_structures_eps(
self,
x: float = None,
y: float = None,
z: float = None,
freq: float = None,
alpha: float = None,
cbar: bool = True,
reverse: bool = False,
ax: Ax = None,
) -> Ax:
"""Plot each of simulation's structures on a plane defined by one nonzero x,y,z coordinate.
The permittivity is plotted in grayscale based on its value at the specified frequency.
Parameters
----------
x : float = None
position of plane in x direction, only one of x, y, z must be specified to define plane.
y : float = None
position of plane in y direction, only one of x, y, z must be specified to define plane.
z : float = None
position of plane in z direction, only one of x, y, z must be specified to define plane.
freq : float = None
Frequency to evaluate the relative permittivity of all mediums.
If not specified, evaluates at infinite frequency.
reverse : bool = False
If ``False``, the highest permittivity is plotted in black.
If ``True``, it is plotteed in white (suitable for black backgrounds).
cbar : bool = True
Whether to plot a colorbar for the relative permittivity.
alpha : float = None
Opacity of the structures being plotted.
Defaults to the structure default alpha.
ax : matplotlib.axes._subplots.Axes = None
Matplotlib axes to plot on, if not specified, one is created.
Returns
-------
matplotlib.axes._subplots.Axes
The supplied or created matplotlib axes.
"""
return self.mode_solver.simulation.plot_structures_eps(
x=x,
y=y,
z=z,
freq=freq,
alpha=alpha,
cbar=cbar,
reverse=reverse,
ax=ax,
)
[docs] def plot_grid(
self,
x: float = None,
y: float = None,
z: float = None,
ax: Ax = None,
**kwargs,
) -> Ax:
"""Plot the cell boundaries as lines on a plane defined by one nonzero x,y,z coordinate.
Parameters
----------
x : float = None
position of plane in x direction, only one of x, y, z must be specified to define plane.
y : float = None
position of plane in y direction, only one of x, y, z must be specified to define plane.
z : float = None
position of plane in z direction, only one of x, y, z must be specified to define plane.
ax : matplotlib.axes._subplots.Axes = None
Matplotlib axes to plot on, if not specified, one is created.
**kwargs
Optional keyword arguments passed to the matplotlib ``LineCollection``.
For details on accepted values, refer to
`Matplotlib's documentation <https://tinyurl.com/2p97z4cn>`_.
Returns
-------
matplotlib.axes._subplots.Axes
The supplied or created matplotlib axes.
"""
return self.mode_solver.simulation.plot_grid(
x=x,
y=y,
z=z,
ax=ax,
**kwargs,
)
[docs] def plot_field(
self,
field_name: str,
val: Literal["real", "imag", "abs"] = "real",
eps_alpha: float = 0.2,
robust: bool = True,
vmin: float = None,
vmax: float = None,
ax: Ax = None,
**sel_kwargs,
) -> Ax:
"""Plot the field for a :class:`.ModeSolverData` with :class:`.Simulation` plot overlaid.
Parameters
----------
field_name : str
Name of `field` component to plot (eg. `'Ex'`).
Also accepts `'E'` and `'H'` to plot the vector magnitudes of the electric and
magnetic fields, and `'S'` for the Poynting vector.
val : Literal['real', 'imag', 'abs', 'abs^2', 'dB'] = 'real'
Which part of the field to plot.
eps_alpha : float = 0.2
Opacity of the structure permittivity.
Must be between 0 and 1 (inclusive).
robust : bool = True
If True and vmin or vmax are absent, uses the 2nd and 98th percentiles of the data
to compute the color limits. This helps in visualizing the field patterns especially
in the presence of a source.
vmin : float = None
The lower bound of data range that the colormap covers. If ``None``, they are
inferred from the data and other keyword arguments.
vmax : float = None
The upper bound of data range that the colormap covers. If ``None``, they are
inferred from the data and other keyword arguments.
ax : matplotlib.axes._subplots.Axes = None
matplotlib axes to plot on, if not specified, one is created.
sel_kwargs : keyword arguments used to perform ``.sel()`` selection in the monitor data.
These kwargs can select over the spatial dimensions (``x``, ``y``, ``z``),
frequency or time dimensions (``f``, ``t``) or `mode_index`, if applicable.
For the plotting to work appropriately, the resulting data after selection must contain
only two coordinates with len > 1.
Furthermore, these should be spatial coordinates (``x``, ``y``, or ``z``).
Returns
-------
matplotlib.axes._subplots.Axes
The supplied or created matplotlib axes.
"""
return self.mode_solver.plot_field(
field_name=field_name,
val=val,
eps_alpha=eps_alpha,
robust=robust,
vmin=vmin,
vmax=vmax,
ax=ax,
**sel_kwargs,
)
