What’s new in our Optical Modeling and Design Software?

With the latest release of the optical modeling and design software VirtualLab Fusion, version 2023.2, a number of new and helpful tools have been added. But the novelty does not stop there: we have also taken this chance to upgrade some of our previously existing features. In this week’s newsletter we put the spotlight on the Field Inside Component: FMM analyzer, a tool that allows the user visualize and investigate the field distribution inside micro- and nanostructures. The analyzer can now also analyze 2D-periodic structures.

Please take a look at the documents below to find an introduction to the Field Inside Component: FMM analyzer as well as an example where we investigate (and go on to optimize) the reflectivity of an anti-reflection moth-eye structure.

While the Distributed Computing Package and the Parameter Variation Analyzer certainly are the highlights of the latest release of the optical modeling and design software VirtualLab Fusion, 2023.2, we have also implemented a whole set of new features and improvements for our result and data visualization, allowing the user a clearer picture of what is going on in the optical system.

Hence, in this week’s newsletter we want to put the spotlight on two of these additions. Please take a look at the documents linked below to find a guide to our Ray-Results 3D System View, the perfect engine to provide a quick overview of how the system is set up and what the light propagation inside it looks like. With this latest release, we have added options to, for instance, filter out any rays that do not pass a specific aperture, as well as new ruler to easily measure distances in the view. The second document tells you all you need to know about how regions work in VirtualLab Fusion, including the multiple new tools to scale, rotate and shift regions.

Multiplexing is a cornerstone of optical design: whether the task is to come up with a setup which can perform its intended function well under different conditions (for example, an augmented-reality device which must work for a certain field of view), or to carry out a tolerance analysis of a given design, it is often desirable to calculate a single merit function which encompasses multiple different configurations of the same system. This helps us characterize the behavior of said system over a certain parameter range with a single measure.

For exactly this purpose, VirtualLab Fusion’s brand-new release 2023.2 introduces the Parameter Variation Analyzer. This flexible and powerful tool offers the capability to process the results of multiple detectors and/or multiple iterations from e.g. a parameter sweep into a freely customizable result, which can then be employed as the merit function of an optimization, for instance.

In the documents below we have prepared for you a deep-dive document into this new feature as well as an application example in the form of a CIGS (copper indium gallium selenide) solar-cell. In this example we use the Parameter Variation Analyzer to combine the values from 4 detectors and finally calculate the energy absorbed in the CIGS layer.

We are proud to announce the release of the latest version of the optical modeling and design software VirtualLab Fusion, 2023.2!

The signature technology of VirtualLab Fusion is its interoperability of modeling techniques on a single software platform, which allows you to have full control of the balance between accuracy and speed that is always an unavoidable aspect of simulation technology. Version 2023.2 expands on this concept, pursuing the development goals we have set ourselves to offer ever higher speed, easier use, more physics, deeper transparency, and more control.

The new release of VirtualLab Fusion – version 2023.2 – is here, and with it come exciting new features. One of the most important, which we would like to highlight in this week’s newsletter, is the Distributed Computing Package.

This tool is aimed at drastically improving simulation times for those complex problems which are composed of multiple elementary simulations, such as parameter sweeps or tolerance analysis. The Distributed Computing Package makes it possible to allocate the individual elementary tasks to different machines (computers/servers) in a network, so that they are calculated in parallel, thus decreasing overall simulation time.

Please take a look at the documents below for a deep dive into the new technology, as well as an application scenario where we drastically improve simulation times for a white-light interferometer example.

Hybrid lenses combine the advantages of classic refractive components and diffractive structures, and hence have become a promising approach in different optical applications, such as intraocular lens implants for treatment of cataracts. In particular, the opposite signs of the dispersion for refractive and diffractive surfaces enable the correction of chromatic aberrations.

In order to model and design such a hybrid element accurately, the in-depth analysis of diffraction effects through the system is a necessity. This includes the evaluation of diffraction efficiencies of real structures in combination with the fast and accurate calculation of the point-spread function (PSF). VirtualLab Fusion’s highly flexible approach of interoperable modeling techniques on a single platform is key to enable the precise and quick modeling of classic lenses and calculation of the diffraction efficiencies of the different orders of a diffractive lens.

To illustrate the capabilities of the software in this regard, the near and far field view of a designed hybrid lens are analyzed in the example. Moreover, the effect of varying the height of the designed binary element on the diffraction efficiencies is investigated to further optimize the optical function. In order to evaluate the resulting PSFs similar to the perception of a human eye, photometric quantities, such as illuminance and luminous flux, are used, which can easily be determined with the help of VirtualLab’s flexible detector concept.

Dot projectors, capable of splitting an incoming beam into a densely populated array of discrete spots, have seen a rapid increase in applications in recent history. To achieve the required high number of spots, these devices typically combine highly divergent source panels with beam splitters.

Striking the right balance between accuracy and speed in the simulation of systems like these can be quite challenging: On the one hand, the small structures of the beam splitter demand the application of rigorous methods, which tend to be computationally heavy. On the other, the simulation should be agile enough to produce results within reasonable bounds of memory use and time. Besides, often, the system will comprise not just the dot projector, but also, at least, propagation in free space, if not other, additional, optical components, such as lenses.

The extremely flexible approach of interoperability of modeling techniques on a single platform offered by the optical modeling and design software VirtualLab Fusion is just the ticket here. It permits the application of the rigorous Fourier Modal Method/Rigorous Coupled Wave Analysis (FMM/RCWA) to model the non-paraxial splitter with the necessary accuracy, while at the same time avoiding computational overkill by combining this technique with other, much faster, approaches for other potential elements in the system, whether they be propagation in free space, through lenses, or both. And all of this on a single software platform with a consistent light model, meaning that no important information is lost changing from one modeling technique to another, and also obviating the need for any cumbersome back-and-forth between different packages.

In this week’s newsletter we showcase just such a dot-projector system, providing both an analysis of the working principle of the device and a document covering its design.

Nonsequential optical systems, particularly those where the nonsequentiality comes from the presence of multiple internal reflections inside a component, pose their own specific set of challenges. Decomposing such systems into a sequential equivalent is often immensely inconvenient, and always impractical. Having an inherently nonsequential modeling strategy at our disposal can, then, become a huge advantage when faced with tasks of this kind.

The modeling and design software VirtualLab Fusion offers precisely this with its Manual Channel Configuration mode, in which the so-called “Light Path Finder” performs a preliminary analysis of the paths that the light follows inside a nonsequential system, using a user-controlled energy-based criterion to determine which paths need to be followed further; this becomes particularly useful in asymptotic configurations with an infinite number of paths. The additional capacity granted to the user to open and close channels in the system at will (e.g., should only forward transmission be considered for this particular interface, or is backward reflection also of interest?) enhances the flexibility of the approach, allowing you to get results that are as accurate as needed, and as fast as possible.

In this week’s newsletter we demonstrate this concept using two different scenarios as examples. First, we show the case of a Herriott Cell, a resonator filled with weakly absorbing gas where a high number of roundtrips facilitates an accurate characterization of the absorption properties of the material. Secondly, we employ a Fabry-Perot etalon to resolve the sodium doublet.