General FAQs

Editions & Toolboxes

What is the difference between VirtualLab Fusion Basic and Advanced?

  • VirtualLab Fusion Basic provides a broad collection of technologies and covers a wide range of applications.
    • Lens systems can be analyzed with not just ray tracing, but also the unique field tracing. All aperture-diffraction effects be can considered within a system, for both imaging and laser systems.
    • The innovative channel concept enables a very convenient mechanism for the modeling of interferometric systems, like Michelson, Mach-Zehnder Interferometers, as well as optical etalons. both imaging and laser systems.
    • VirtualLab Fusion Basic covers topics like ultrashort pulse modeling, VCSEL modeling, fiber coupling analysis, and so on.
    • It is even customizable! With the inbuilt user-friendly programming language, or also via others like Python and Matlab, the modeling and design possibilities can be further extended.
  • With all the technologies from the Basic edition, VirtualLab Fusion Advanced adds the Fourier Modal Method (FMM, a.k.a. RCWA) as a rigorous vectorial method for modeling periodic structures (1D and 2D).
    • It includes pre-defined models for surface-relief gratings, holographic volume gratings, and even metagratings.
    • One can analyze either the diffraction properties of an isolated grating device, or check its performance when used together with other components in a system.

I purchased the Starter Toolbox and the Non-Sequential Extension. What will happen now?

  • If you purchased the Starter Toolbox, your license will automatically be changed to VirtualLab Fusion Basic.
  • The Non-Sequential Extension is now also part of VirtualLab Fusion Basic.

What is the difference between Silver and Gold Version of the Diffractive Toolbox?

  • The Diffractive Optics Toolbox Silver is a practical tool for diffractive beam splitter, diffuser, and beam shaper design, based on the iterative Fourier transform algorithm (IFTA). It requires VirtualLab Fusion Basic edition. All standard merit functions for performance evaluation are provided, as well as options for basic fabrication tolerance analysis.
  • In addition to the Silver edition, the Diffractive Optics Toolbox Gold, with the local linear grating approximation (LLGA) technology, makes it a unique tool for the modeling of diffractive lenses and holographic optical elements (HOEs). It requires VirtualLab Fusion Advanced. A complete and closed workflow is provided: from import of e.g. binary 2 surfaces from Zemax® OpticStudio® to the export of the actual diffractive lens surface data.

What is the difference between Silver and Gold Version of the Light Guide Toolbox?

  • The Light Guide Toolbox Silver is a market-leading tool for the modeling of light-guide-based display systems. It features modeling of multiple grating regions for high-quality AR/MR applications. It requires VirtualLab Fusion Advanced. Based on the Fourier modal method (FMM, a.k.a RCWA), the grating response (including direction, wavelength, and polarization) is fully included in the calculation.
  • The Gold edition provides the world’s first grating design algorithm for common light guide layouts, that greatly speeds up product design cycles. It requires VirtualLab Fusion Advanced. It assists with light guide design, by starting from a visualization of the principle in the k-domain and then generating the geometry of the layout.


What are the highlights of the VirtualLab Fusion Release 2020.2?

Regions with Modulated Grating Parameters

  • It is now supported to define gratings with modulated grating parameters within the regions on the surfaces of a light guide.​

New Surface Types

  • We implemented the following new surface types: Anamorphic Asphere, Q-Type Asphere Surface and Toroidal Asphere Surface. The import of the corresponding surface from Zemax is also available.

And many more....

  • Besides these developments and improvements, we also did major changes in the source code editor. Snippets now show the former Additional Usings, Snippet Body Main Function together in one document with read-only parts and Syntax errors and warnings are highlighted.

System Requirements

What system requirements are necessary to run VirtualLab Fusion?

  • Operating system: Windows 8.1; Windows 10 (1607 or higher); Windows Server 2012 R2 / 2016 / 2019. 64-bit edition required. Preview versions are not supported.
  • CPU: Quad-core processor with at least, 2.4 GHz, recommended at least octa-core processors with 3 GHz
  • RAM: 8 GB, recommended at least 32 GB
  • Hard disk space: 50 GB, recommended 250 GB SSD drive
  • Graphics adapter: resolution 1920 × 1080 or higher, recommended 2 GB video RAM
  • Interface: USB-A port and internet

I am a Mac User. Can I run VirtualLab Fusion on Mac?

VirtualLab Fusion is a software application for Windows operating systems. It is possible to run VirtualLab Fusion on Apple computers with OS X with an Intel CPU. You can install Windows on an extra partition with the help of the Apple Boot Camp software. Alternatively, you can of course work on a virtual machine that runs a Windows operating system.


When does the license expire if a new toolbox is added to an existing VirtualLab Fusion license?

If you add a new toolbox to an existing license, the deadline is the same as that for the existing license. If you want to avoid this, you can split the licenses. Please note, however, that you can not use the two (or more) different licenses at the same time.

Can I buy additional toolboxes later?

You can still buy more toolboxes retrospectively if you need more applications. As a matter of course we give you advice which toolboxes are best suited for you and your applications before your purchase.

Can I still use a license without the update?

Yes, you can continue using the software. However, we cannot guarantee that the software will work properly without an update. In general, you buy the software and do not rent it.

I would like to use the software only for a certain period of time. Is it possible to rent the software instead?

In addition to the new license, VirtualLab Fusion offers a term license (rent). The term license is provided in units of 3 months.

Are the individual toolbox stand-alone?

Our product policy regarding the toolbox concept changed a bit. We offer you the Fast Physical Optics Software Platform VirtualLab Fusion in the editions Basic and Advanced. On this basis you can expand your capabilities by adding different toolboxes (e.g. Diffractive Optics Toolbox, Light Guide Toolbox).​
Each toolbox can be used individually. Depending on the application, you can combine the toolboxes and analyze together. Toolboxes are specialized for certain (complex) system modeling and design tasks.

Get Technical Support

I have a technical question regarding VirtualLab Fusion. How do I get support?

Writing an email is the best way to get technical support. Please include your license number and share a copy of the file where your question / problem can be seen. Please send the mail to support (at) Our support team will reply to you as soon as possible.

I lost my hardlock / dongle. How can I replace a lost or stolen license?

Please contact us ( as soon as you notice that your license is missing.


How can I get deeper insights into a specific topic?

We offer many possibilities to increase your VirtualLab Fusion skills:

  • Our freely available video tutorials can help you enjoy a smooth first contact with VirtualLab Fusion.
  • From time to time we offer webinars.
  • Additionally, you can attend our training courses and seminars at different locations:
    • Public training courses – they regularly take place in different locations worldwide.
    • On-site training courses – tailored to your individual requirements.
    • Free seminars – find an event in your region!

Do you also offer on-site training courses?

We also offer on-site training courses tailored to your needs and requirements, with the added possibility to turn the event into an online training course, should you so wish. For more information, please send an email to sales (at) including a description of what you expect from the course and an indication of your preferred dates and time.

Trial Version

I would like to get a first feeling for how the software works. Are there any limitations to the trial version?

Our trial version offers many possibilities to test and play around with. However, some features are not included in the trial version.

  • Saving of documents to the hard disk is disabled. However, support files of light path diagrams can be saved. Those files can be sent to LightTrans for support purposes.
  • Programming of snippets, programmable components and programmable detectors is disabled. However, snippets, programmable components and programmable detectors provided as part of documents (light path diagrams, parameter run) or in catalogs can be used.
  • C# modules cannot be executed.
  • The software can be started 50 times, each session is limited to a duration of 12 hours.
  • A special license agreement that excludes commercial use of results is in effect for the trial version.

If you have further questions regarding the trial version, please feel free to contact our sales team.


How does the search function work on your webpage?

In general, we have two different search functions in our webpage: the Global Search function and the search function in our Download Area. Both are based on different search algorithms. This means that each search function may give different outcomes.

It is highly recommended to use the Global Search function. For a detailed description and more information, please have a look at this document.

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Contact & Trial

LightTrans GmbH

Phone +49.3641.53129-50

info (at)


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