Data-Based Source [x-Domain]¶

Description¶

The Data-Based Source [x-Domain] twin provides a flexible way to introduce custom light sources into your VirtualLab Fusion simulations. Instead of defining a source with analytical formulas, you load the complete electromagnetic field data---specifically a 2D data array containing both \(E_x\) and \(E_y\) components, along with the wavefront phase---from an external file or from a field calculated in another optical setup. This allows you to faithfully reproduce any arbitrary optical field, whether it originates from a complex simulation or from real-world measurements, and use it as the starting point for a new system.

Model Parameters¶

The twin is configured by providing the following data. All data must be defined on a consistent 2D grid (same sampling and number of points).

• Electromagnetic Field: A single 2D data array containing two subsets---one representing the \(E_x\) component and one representing the \(E_y\) component of the electric field in the spatial domain. This array fully defines the field's amplitude, polarization, and component-specific phases.
• Wavefront Phase \(\psi(\rho)\): A real-valued array representing the common wavefront phase. This is the phase shared by all field components, typically arising from optical path length differences. If no wavefront phase is provided, a planar wavefront (constant phase) is assumed.

Note: The wavelength \(\lambda\) of the source is not part of the loaded field data. It is configured as a separate parameter in the source's spectrum settings (see Software Usage).

Simulation Model¶

From the provided \(E_x\) and \(E_y\) components, all other relevant field quantities can be derived to fully characterize the source. This ensures a complete and physically consistent electromagnetic field description for subsequent propagation through the optical system.

Typical Application Scenarios¶

1. Cascading Optical Systems: Use the output field from a complex simulation (e.g., light passing through a diffuser or a multi-lens system) as the input source for a subsequent optical system, enabling true multi-stage simulations.
2. Importing Measured Beam Profiles: Load experimentally measured beam data (amplitude and phase) into the simulation to analyze how a real-world beam will propagate through or interact with your optical design.
3. Simulating Custom Laser Modes: Create a source for a specific, non-standard laser mode by generating its field profile with an external tool (e.g., MATLAB, Python) and importing it for use in VLF.

Software Usage¶

1. Prepare Field Data: Obtain your electromagnetic field data (the combined \(E_x\)/\(E_y\) array) and the optional wavefront phase \(\psi(\rho)\). This data can be:
   • Imported from an external file (ensure the format is compatible with VLF's data import tools).
   • Calculated in another VLF optical setup and captured using a Field Monitor detector, which can directly provide the wavefront phase.
2. Add the Twin: From the Digital Twin Hub, search for "Stored Source" or code SF-SDAT01 and add the twin to your document.
3. Load Field Data:
   1. Open the source's settings dialog.
   2. Navigate to the Spatial Distribution tab.
   3. Click the "Set" button next to the field data options.
   4. Load your combined \(E_x\)/\(E_y\) array. If you have a wavefront phase array, load it in the designated field. If none is loaded, a planar wavefront is assumed.
4. Set the Spectrum: Go to the Spectrum tab in the source's settings and set the correct wavelength \(\lambda\).
5. System Integration: Connect the source twin to other components (lenses, objects) and detectors to build your system and analyze the propagation of your custom field.