GaussianPort

GaussianPort(
    center,
    input_vector,
    waist_radius,
    waist_position=0,
    polarization_angle=0,
    field_tolerance=0.001,
    *,
    waist_distance=None,
)

Gaussian beam port.

This 3D port models a Gaussian beam that can be used, for example, for grating and edge couplers. It must be placed in a homogeneous medium.

Args

• center (Sequence[float]): Port position in 3D.
• input_vector (Sequence[float]): 3D input vector (beam propagation direction).
• waist_radius (float): Waist radius of the beam.
• waist_position (float): Waist position along the input direction. Positive (negative) values result in the waist being in front of (behind) the input plane.
• polarization_angle (float): Polarization angle (in degrees) for the electric field with respect to the plane formed by the input direction and the largest input direction component (in absolute value). If the input direction is aligned to one of the Cartesian axes, this plane is not well-defined and the angle is measured from the x axis for inputs in y or z, and measured from y for input in x.
• field_tolerance (float): Relative field magnitude used to define the size of this port. The port dimensions are defined such that the field magnitude at the boundaries are below this level with respect to the maximum.
• waist_distance (float | None): Distance from the beam waist to the input plane. Positive (negative) values indicate that the distance is measured towards the positive (negative) global axis, i.e., if the beam waist is at the origin, the input plane is on the positive (negative) side of the axis.

Note

Arguments waist_position and waist_distance represent the same specification with different conventions. Only one must be specified. For convenience, waist_distance matches Tidy3D’s GaussianBeam.waist_distance definition.

Argument polarization_angle has the same meaning as Tidy3D’s GaussianBeam.pol_angle, except that it is defined in degrees, not in radians.

See Also

Grating Coupler

Methods

Method	Description
copy	Create a copy of this port.
fields	Calculate the fields from this Gaussian beam.
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_monitor	Create a Tidy3D GaussianOverlapMonitor from this port.
to_tidy3d_source	Create a Tidy3D GaussianBeam from this port.

copy

copy(self, deep=False)

Create a copy of this port.

Args

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

Returns

GaussianPort: New copy.

fields

fields(self, x, y, z, frequency, medium=1.0)

Calculate the fields from this Gaussian beam.

Args

• x (float | Sequence[float]): Coordinate in x for field computation.
• y (float | Sequence[float]): Coordinate in y for field computation.
• z (float | Sequence[float]): Coordinate in z for field computation.
• frequency (float | Sequence[float]): Frequency for computation.
• medium (MediumType | Sequence[float] | float): Tidy3D medium or relative permittivity of the port background medium as a single value or a sequence with one value for each frequency.

Returns

tuple[ndarray, ndarray, ndarray, ndarray, ndarray]: Complex field amplitudes, electric and magnetic normalization coefficients, and electric and magnetic polarization vectors.

Note

The returned amplitude is a 2-dimensional numpy array with shape (F, N), in which F and N are the sizes of the frequency and the coordinates sequences, respectively.

The normalization coefficients are arrays with one element per frequency value (size F).

Arguments x, y, and z must all have the same size N or be a single value.

Each component of the electric (magnetic) field can be obtained by multiplying the complex amplitude by the electric (magnetic) normalization coefficient and the corresponding vector component.

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

GaussianPort: Reflected Gaussian port.

to_tidy3d_monitor

to_tidy3d_monitor(self, frequencies, name, medium=1.0)

Create a Tidy3D GaussianOverlapMonitor from this port.

Args

• frequencies (Sequence[float]): Frequencies for the field monitor.
• name (str): Name for the created monitor.
• medium (MediumType | Sequence[float] | float): Tidy3D medium or relative permittivity of the port background medium as a single value or a sequence with one value for each frequency.

Returns

tidy3d.FieldMonitor: Tidy3D FieldMonitor.

to_tidy3d_source

to_tidy3d_source(self, frequencies, name=None, medium=1.0)

Create a Tidy3D GaussianBeam from this port.

Args

• frequencies (Sequence[float]): Frequencies for the source.
• name (str | None): Optional name for the created source.
• medium (MediumType | Sequence[float] | float): Tidy3D medium or relative permittivity of the port background medium as a single value or a sequence with one value for each frequency.

Returns

tidy3d.GaussianBeam: Tidy3D Gaussian beam.

Attributes

Attribute	Description
added_solver_modes	int: Additinal modes to include in mode solver runs for this port (read only).
center	ndarray: Gaussian port center.
classification	Literal[“optical”, “electrical”]: Port classification: optical or electrical (read only).
field_tolerance	float: Gaussian beam field tolerance.
input_vector	ndarray: Gaussian port input direction.
num_modes	int: Number of modes supported by this port (read only).
polarization_angle	float: Gaussian beam polarization angle.
properties	Properties: Object properties.
waist_distance	float: Gaussian beam waist distance.
waist_position	float: Gaussian beam waist position.
waist_radius	float: Gaussian beam waist radius.

added_solver_modes

int: Additinal modes to include in mode solver runs for this port (read only).

center

ndarray: Gaussian port center.

classification

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

field_tolerance

float: Gaussian beam field tolerance.

input_vector

ndarray: Gaussian port input direction.

num_modes

int: Number of modes supported by this port (read only).

polarization_angle

float: Gaussian beam polarization angle.

properties

Properties: Object properties.

waist_distance

float: Gaussian beam waist distance.

waist_position

float: Gaussian beam waist position.

waist_radius

float: Gaussian beam waist radius.