# AstigmaticGaussianOverlapMonitor
Monitor that records the overlap integral between simulated fields and an astigmatic Gaussian beam profile. The astigmatic Gaussian beam allows both an elliptical intensity profile and different waist locations for the two principal axes of the ellipse. When equal waist sizes and equal waist distances are specified in the two directions, this monitor becomes equivalent to GaussianOverlapMonitor.
# 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
# Waist Sizes
waist_sizes: Size of the beam at the waist in the local x and y directions.
Type: floating-point number
- Unit: m, μm (default), or nm
- Constraint: greater than 0
- Default: (1, 1)
# Waist Distances
waist_distances: Distance to the beam waist along the propagation direction for the waist sizes in the local x and y directions. Positive values place the waists behind the monitor plane, while negative values place them in front of the monitor plane.
Type: floating-point number
- Unit: m, μm (default), or nm
- Default: (0, 0)
# Polar Angle
angle_theta: Polar angle of the propagation axis from the injection axis.
Type: floating-point number
- Unit: rad or degree (default)
- Default: 0
# Azimuth Angle
angle_phi: Azimuth angle of the propagation axis in the plane orthogonal to the injection axis.
Type: floating-point number
- Unit: rad or degree (default)
- Default: 0
# Polarization Angle
pol_angle: Specifies the angle between the electric field polarization and the plane defined by the injection axis and the propagation axis.
- 0 specifies P polarization (default)
- 90 degrees or π/2 rad specifies S polarization
Type: floating-point number
- Unit: rad or degree (default)
- Default: 0
# 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 THz (default) or Hz.
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)
# Colocate Fields
colocate: Toggle whether fields should be colocated to grid cell boundaries (i.e. primal grid nodes).
Options:
- False: Fields will NOT be colocated to grid cell boundaries.
- True: Fields will be colocated to grid cell boundaries.
Default: True
# Use Colocated Integration
use_colocated_integration: Toggle whether monitor integration uses colocated fields.
Options:
- False: Use the native Yee-grid field locations.
- True: Use fields colocated to grid cell boundaries.
Default: True
# Conjugated Dot Product
conjugated_dot_product: Use conjugated or non-conjugated dot product for the overlap integral computation.
Options:
- False: Use non-conjugate dot product.
- True: Use conjugate dot product.
Default: True
# 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
# Store Fields
store_fields_direction: Select whether to store the astigmatic Gaussian beam field datasets and, when enabled, which direction to store. This is controlled by Store Fields.
Options:
- None (default): It means that Store Fields is unchecked and the field datasets will NOT be available in simulation results.
- +: It means that Store Fields is checked and the field datasets will be available in simulation results for the + (Forward) propagation direction.
- -: It means that Store Fields is checked and the field datasets will be available in simulation results for the - (Backward) propagation direction.