Wavefront Phase Modifier [Surface, Output-Defined]¶
1 Purpose¶
The Wavefront Phase Modifier [Surface, Output-Defined] combines the surface handling of the Surface, Profile-Defined variant with the output-defined concept of the Plane, Output-Defined variant.
The requested output wavefront phase is defined in the reference \(xy\) plane and internally propagated onto the selected WPM surface. There, the required wavefront phase profile is determined from the requested output wavefront phase and the incoming wavefront phase:
The resulting profile is then applied on the curved surface. This twin is useful when the target output wavefront is known but the required phase profile on a curved surface is not obvious.
2 Geometric Support¶
This twin is defined on a curved reference surface. The user selects the reference surface from the available surfaces in the optical setup. The requested output phase is defined in the reference plane and internally propagated onto the selected surface.
Model Context: Output Propagation to Surface¶
The requested output phase is defined in the reference plane and propagated onto the WPM surface with respect to the twin coordinate system. The local coordinate transformation is handled internally.
3 Supported Channels¶
This twin supports illumination from the front side only. The user selects either the transmission (T) or reflection (R) channel as the active output channel. The selected channel is the only generated output; the opposite channel is not generated. The requested output phase is defined for the selected channel.
4 Simulation Model¶
This is a function-based optical digital twin with an in-built design capability. It computes the required wavefront phase profile from the requested output wavefront phase and the incoming wavefront phase on the curved surface, then applies the computed profile.
The twin includes an aperture option: the user can select whether the component is used as Single Function without Aperture or Single Function with Aperture. The aperture is applied on the reference surface before the phase modification.
5 Parameters Where This Sheet Adds Guidance¶
The complete parameter documentation is available in the VirtualLab Fusion manual and from the twin via Help. This sheet only lists parameters for which additional modeling interpretation, usage guidance, or cross-twin selection advice is useful.
Requested Output Wavefront Phase¶
Role: Specifies the desired output wavefront phase \(\psi^{\mathrm{out}}\) in the reference plane.
Spec-sheet insight: The component internally propagates the requested phase onto the selected surface and computes the required profile. Three input formats are available: Even Order Radial Polynomial, User-Defined Formula, and Data Based.
Reference Surface¶
Role: Selects the curved surface on which the phase is applied.
Spec-sheet insight: The user can load, edit, or view the selected surface. The requested output phase is propagated onto this surface.
Flip Output Phase Sign¶
Role: Inverts the sign of the specified output wavefront phase.
Spec-sheet insight: Use this to correct a wrong sign setting without redefining the desired output.
Selected Output Channel¶
Role: Selects the active output channel: Transmission or Reflection.
Spec-sheet insight: The requested output phase is defined for the selected channel. Only the selected channel is generated.
Consider Phase Effect Only¶
Role: Ignores amplitude and polarization effects from energy conservation.
Spec-sheet insight: Use this for studying the pure phase effect in isolation.
Display Wavefront Profile Data After Simulation¶
Role: Outputs the internally computed wavefront phase profile.
Spec-sheet insight: The displayed data shows the profile that was applied, not the requested output phase.
6 Recommended Usage¶
- Use this twin when the desired output wavefront is known and the phase profile must be applied on a curved surface.
- Use the Even Order Radial Polynomial format for rotationally symmetric output phases.
- Use the Data Based format for output phases from measurements or external simulations.
- Use the Display Wavefront Profile Data After Simulation option to verify the internally computed profile.
- Use the Consider Phase Effect Only flag for pure phase studies.
7 Related Twins¶
Related twins belong to the same function-based family or to closely neighboring function-based variants.
| Related Twin | Main Distinction |
|---|---|
| Wavefront Phase Modifier [Surface, Profile-Defined] | Same surface geometry; profile is supplied directly. |
| Wavefront Phase Modifier [Plane, Profile-Defined] | Profile-defined concept on a plane. |
| Wavefront Phase Modifier [Plane, Output-Defined] | Output-defined concept on a plane. |
8 Possible Replacement Twins¶
Replacement twins provide another modeling route for the same design intention.
| Possible Replacement Twin | When It Replaces This Twin |
|---|---|
| Wavefront Phase Modifier [Surface, Profile-Defined] | Use when the required profile is already known and can be supplied directly. |
| Holographic Optical Element (HOE) Twin | Use when the phase profile should be realized by a diffractive structure on a curved substrate. |
| Refractive Surface Twin | Use when the phase profile should be realized by a curved refractive surface. |
9 Further Reading¶
For complete software parameter documentation, see the VirtualLab Fusion manual, Sec. 69.9, Wavefront Phase Modifier [Surface, Output-Defined].
For the theoretical foundations of the Wavefront Phase Modifier family see the white paper on From Phase to Structure: A Two-Step Design Workflow with Wavefront Phase Modifier Twins (LightTrans Document ID: WP-WPM-PUB).