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Defining the Source Power (Radiant Flux) in VirtualLab Fusion!

🎬 Overview

In VirtualLab Fusion (VLF) the user can specify a power value for the light source. It refers to the radiant flux going through the input plane of the source with its given aperture. This tutorial describes the procedure for configuring the source power.

⚠️ Important: The power management settings are only available when using the Field Tracing engine as radiant flux is not defined for the results provided by the Ray Tracing engine.

  1. Open the Profile Editor of your Optical System

  2. Activate Power Management under Sources › Power Management

  3. Set the Source Modeling Power (radiant flux directly after the source)

  4. Validate the power using a field monitor and the Radiant Flux detector add‑on

🚀 Step‑by‑Step Tutorial

Step 1: Open the Source Profile Editor

Select your Optical System. Under Profile Editing & Run click Profile Editor.

Step 1: Click Profile Editor under Profile Editing & Run
Step 1: Click Profile Editor under Profile Editing & Run

Step 2: Navigate to Power Management and Activate Power Management

Within the Profile Editor, go to the Sources section and select Power Management. Check the box „Activate Power Management“.

This enables manual control over the source’s radiant flux.

Step 2: Activate Power Management
Step 2: Activate Power Management

ℹ️ Note: This tab appears only when the Field Tracing engine is selected. If you are using the Ray Tracing engine, the tab is hidden.

Step 3: Set the Source Modeling Power

Enter the desired value in the field „Source Modeling Power“.

Parameter Meaning
Source Modeling Power Radiant flux (in watts) directly after the source, before any propagation or interaction with optical components.

This value corresponds to the total optical power emitted by the source.

Step 3: Set Source Modeling Power
Step 3: Set Source Modeling Power

Step 4: (Optional) Configure the Type of Power Spectrum

If your source contains multiple wavelengths, the parameter „Type of Power Spectrum“ becomes relevant.

Setting Description Typical Use Cases
Discrete The sampled spectrum consists of discrete Dirac delta functions at the defined wavelength positions. Laser lines (e.g., mercury vapor lamp); RGB laser projector
Continuous The spectrum is treated as a continuous, linearly interpolated curve between the sampled wavelengths. Sunlight, broadband LED, halogen lamp, thermal radiator (blackbody)

For monochromatic light sources, this setting has no practical effect and can be ignored.

Step 4a: Example of an RGB source.
Step 4a: Example of an RGB source.
Step 4b: RGB source with discrete spectrum.
Step 4b: RGB source with discrete spectrum.
Step 4c: RGB source with continous spectrum.
Step 4c: RGB source with continous spectrum.

⚠️ Important: The power management settings are specified for an individual source. If you include a new source into your optical system, these steps need to be repeated.

Step 5: Set/Check Source Aperture

Most sources in VirtualLab Fusion are equipped with an aperture, which can be defined in the settings. As the specified radiant flux is assigned to the input field passing through this aperture, you should ensure that these settings correspond to your intended purpose.

Step 5: Aperture of an Gaussian Wave Mode.
Step 5: Aperture of an Gaussian Wave Mode.

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Tags: radiant flux power management source modeling power field tracing VirtualLab Fusion