# FieldProjectionAngleMonitor

Monitor that samples electromagnetic near fields in the frequency domain and projects them at given observation angles.

Please refer to this example (opens new window) for detailed instructions on how to use this monitor.

# Name

name: Unique name for monitor.

Required field

# Size and Position

Specification of the monitor size and position.

# Center + size

Object definition through a center position and size.

center: Center of the object in x, y, and z-directions.

Type: floating-point number

  • Unit: m, μm (default), or nm
  • Default: (0, 0, 0)

size: Size of the object in x, y, and z-directions.

Use Infinity to define a geometry extending to infinity in both directions along an axis.

Type: floating-point number

  • Unit: m, μm (default), or nm
  • Constraint: greater than or equal to 0
  • Required field

# Bounds

Object definition through minimum and maximum coordinate bounds.

min: Values of the x, y, and z coordinates defining the object lower corner.

Type: floating-point number

  • Unit: m, μm (default), or nm
  • Required field

max: Values of the x, y, and z coordinates defining the object upper corner.

Type: floating-point number

  • Unit: m, μm (default), or nm
  • Required field

# Frequencies

Definition of the monitor wavelengths/frequencies.

Options:

  • Wavelengths: Specify monitor wavelengths in units of m, μm (default), or nm.
  • Frequencies: Specify monitor frequencies in units of Hz (default) or THz.

Default: Wavelengths

# Enter wavelength/frequency range

Create an evenly spaced list of wavelength/frequency points between a minimum and a maximum value.

min: Minimum wavelength/frequency value.

  • Required field Default: None

max: Maximum wavelength/frequency value.

  • Required field Default: None

number of points: Number of wavelength/frequency points.

  • Required field Default: None

# Custom wavelength/frequency list

Create a custom list of wavelength/frequency points. Click the Edit list button to include, edit, or exclude wavelength/frequency values from the list.

# Downsampling

interval_space: Number of grid step intervals between monitor recordings.

  • If equal to 1, there will be no downsampling.
  • If greater than 1, fields will be downsampled and automatically colocated.

Type: integer

  • Unit: unitless
  • Constraint: greater than 0
  • Default: (1, 1, 1)

# Polar Angles

theta: Polar angles relative to local_origin at which to compute far fields.

Options:

  • degree: Specify the angles in degrees (default).
  • rad: Specify the angles in rad.

Default: degrees

# Enter angle range

Create an evenly spaced list of angles between a minimum and a maximum value.

min: Minimum angle value.

  • Required field Default: 0

max: Maximum angle value.

  • Required field Default: 180 or π

number of points: Number of angles.

  • Required field Default: None

# Custom angle list

Create a custom list of angles. Click the Edit list button to include, edit, or exclude angles from the list.

# Azimuth Angles

phi: Azimuth angles relative to local_origin at which to compute far fields.

Options:

  • degree: Specify the angles in degrees (default).
  • rad: Specify the angles in rad.

Default: degrees

# Enter angle range

Create an evenly spaced list of angles between a minimum and a maximum value.

min: Minimum angle value.

  • Required field Default: 0

max: Maximum angle value.

  • Required field Default: 360 or 2π

number of points: Number of angles.

  • Required field Default: None

# Custom angle list

Create a custom list of angles. Click the Edit list button to include, edit, or exclude angles from the list.

# Apodization

Sets parameters of (optional) apodization. Apodization applies a windowing function to the Fourier transform of the time-domain fields into frequency-domain ones, and can be used to truncate the beginning and/or end of the time signal, for example to eliminate the source pulse when studying the eigenmodes of a system.

Note: apodization affects the normalization of the frequency-domain fields.

start: Defines the time at which the start apodization ends.

Type: floating-point number

  • Unit: s (default), ps, or fs
  • Constraint: greater than or equal to 0

Default: None

end: Defines the time at which the end apodization begins.

Type: floating-point number

  • Unit: s (default), ps, or fs
  • Constraint: greater than or equal to 0

Default: None

width: Characteristic decay length of the apodization function.

Type: floating-point number

  • Unit: s (default), ps, or fs
  • Constraint: greater than or equal to 0

Default: None

# Normal Vector Orientation

normal_dir: Direction of the surface monitor’s normal vector w.r.t. the positive x, y or z unit vectors. Must be one of + or -. Applies to surface monitors only, and defaults to + if not provided.

Options:

  • +
  • -

Default: None, which means

  • None for volume monitors
  • + for surface monitors

# Far Field Approximation

far_field_approx: Whether to enable the far field approximation when projecting fields. If the far-field approximation is used, results projected to points close to the monitor’s position, compared to its size, may not be accurate.

Type: boolean

  • Default: True

# Excluded Surfaces

exclude_surfaces: Surfaces to exclude in the integration, if a volume monitor.

Options: select one or more of

  • x-
  • x+
  • y-
  • y+
  • z-
  • z+

Default: None

# Projection Distance

proj_distance: Radial distance of the projection points from local_origin.

Type: floating-point number

  • Unit: m, μm (default), or nm
  • Default: 1000000.0

# Local Origin

custom_origin: Local origin used for defining observation points. If None, uses the monitor’s center.

Type: floating-point number

  • Unit: m, μm (default), or nm
  • Default: None

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