light path diagram

                optical system

              interferometer

        spatial light modulator

      subwavelength grating

              fiber coupling

              high na lens

                  grin lens

      focused beam

   

VirtualLab Fusion applications include laser systems, imaging systems, projection systems, interferometers, spectrometers, microscopes, telescopes, wafer inspection, ultrashort pulse propagation, pulse stretching and compression, laser resonators and more.

Components in these systems can include: mirrors, refractive lenses, diffractive lenses, hybrid refractive-diffractive lenses, spatial light modulators, microlens arrays, freeform surfaces, high NA optics, grin media, 2D/3D gratings, subwavelength gratings, volume holographic gratings, Bragg gratings and lightguides.

VirtualLab Fusion software includes both ray tracing and physical optics. It does fully vectorial solution of Maxwell's equations, to analyze diffraction, interference, polarization, wavefront aberrations and temporal and spatial coherence. For optical system applications in which the accuracy of ray tracing is increasingly affected by these issues, VirtualLab is a practical simulation and design software tool. It is an integrated software suite that is used for all the components in optical systems from microscale to macroscale.

The free space propagation methods included in VirtualLab Fusion are: Spectrum of plane waves operator (rigorous), Fresnel operator, Far field operator and Geometrical optics operator. These propagation methods are selectively applied in different regions of the optical system by an Automatic Operator Selection algorithm. The goal of the algorithm is to apply the propagation method with the lowest error and lowest numerical effort. Users can override the automatic selection as well. For more information on propagation methods and the Automatic Operator Selection algorithm, please use the "click here" or "Contact us" buttons on this page.

The VirtualLab Starter Toolbox program is for modeling an entire optical system, including light sources, all optical elements, detectors and analyzers. A light path diagram is created in the Starter Toolbox program, and each element in the light path can be edited as needed, including: distances, focal lengths, sizes, positions, angles, and more.

The light path diagram can include optical elements from VirtualLab catalogs (see below) or other VirtualLab Toolbox programs, such as the Diffractive Optics Toolbox, Grating Toolbox, Light Shaping Toolbox, and Laser Resonator Toolbox. For example, some users do rigorous analysis with the Diffractive Optics Toolbox or Grating Toolbox, and then insert the final component into the light path using the Starter Toolbox. VirtualLab Fusion is an integrated software suite of programs for modeling all the microscale and macroscale components in an optical system.

Catalogs in the Starter Toolbox program include boundary responses, coatings, components, detectors, interfaces, light sources, materials, media, and stacks (for gratings). Catalog items can be previewed and edited. User-defined items can also be added to catalogs. For more information on catalog usage in VirtualLab, please submit a request below.

Custom components can also be inserted into the light path diagram. They can be components from the VirtualLab library of C# program snippets, or user-created C# programs created in the VirtualLab editor. Snippets from the VirtualLab library can be edited for customization.

Optical components created in MATLAB can be inserted into the VirtualLab light path diagram. For more about programming, click on the following: Programming and customization, C#, MATLAB, and more

VirtualLab can import data from Zemax, including: lens data, glass data, beam files, and binary 1/2 surfaces. VirtualLab can convert Zemax beam files (irradiance and phase) to fully vectorial electromagnetic field information. Zemax surface phase data can be used in VirtualLab to design multi-level diffractive lenses and metalenses.

Code V vectorial field data can be imported by VirtualLab. Both the real and imaginary parts of the x, y, z components of the electromagnetic field can be imported.

The Starter Toolbox program includes nine calculators for computing and visualizing information. These are: ABCD Law Calculator, Diffraction Angle Calculator, Direction Converter, Fresnel Effects Calculator, Laser Beam Calculator, Modulation Depth Calculator, Vector & Coordinate System Viewer, Coherence Time and Length Calculator, and Debye-Wolf Integral Calculator.

For more information about these calculators contact HMS Technology Sales.

The Parameter Run is very helpful for tolerancing and optimizing optical systems over a minimum/maximum range of user-defined values. Users can vary, distances, positions, sizes, angles, wavelengths, and many more parameters, either individually or in combinations. The parameters can be varied in four different ways: standard, programmed, scanning, and random (Monte Carlo). The results can be exported to Excel.

More detailed information and examples are available about the Parameter Run and tolerancing, so please request it below, if you are interested.

VirtualLab is an integrated software suite of programs for modeling all the microscale and macroscale components in an optical system.

  propagation channels

      interferometer

          telescope

  non-sequential optics

          lightguide

The VirtualLab Non-Sequential Extension works along with the Starter Toolbox program for simulating and designing interferometers, telescopes, prisms, etalons, light guides and other optical systems that require reflections, interference, and split and folded light paths.

The Non-Sequential Extension is also for analyzing unwanted reflections, ghost images and stray light.

Sequential or non-sequential propagation channels can be defined at each surface in the optical system, as shown at the left.

Non-sequential propagation is available for both ray tracing and field tracing (fully vectorial physical optics).

Here is how it works. At each surface, a propagation channel is defined according to the way light propagates at that surface. Forward, left-to-right, propagation is defined as a + channel, and right-to-left propagation is defined as a - channel. One of four propagation possibilities is configured for each surface. These are a +/+, +/-, -/-, or -/+ channel, as shown in the first figure on the left. Example 1: A +/+ channel means light propagates from left-to-right direction to a surface and continues in the same direction. Example 2: A +/- channel means light propagates from left to right to the surface, then reflects in the opposite direction. Example 3: A -/- channel means light travels right to left to that surface and continues in the same direction. Example 4: A -/+ channel means light travels from right to left to that surface, and then reflects from left to right.

In addition to propagation channel directions, the Non-Sequential Extension allows setting energy thresholds, maximum energy values and channel accuracy resolutions.

Non-sequential propagation is quick to set up, and it gives accurate analysis of those applications that include, interference, split or folded light paths, and those optical systems that are degraded by reflections, ghost images or stray light. The VirtualLab Non-Sequential Extension, along with the Starter Toolbox program, simplifies modeling realistic propagation through the light path.

Ask to see examples of non-sequential applications.

        refractive beam shaper

          diffractive lens

      diffractive beam shaper

  beam shaping and splitting

      spatial light modulator

VirtualLab software offers several ways to simulate and design beam shaping optics. The preferred method is determined by factors, such as: coherence of the source, color quality in the image and NA of the optics. The following describes the types of beam shaping optics and the VirtualLab Toolbox programs for these beam shapers.

Refractive beam shapers can be designed with the VirtualLab Starter Toolbox. Examples are: microlens arrays, aspherical lenses and freeform optics.

The VirtualLab Diffractive Optics Toolbox program is for laser beam shaping, beam homogenization and beam splitting. Diffractive Optical Elements can be simulated, designed and optimized. These DOEs are sometimes called diffractive diffusers, computer-generated holograms or kinoforms.

For beam shaping and homogenization of partially coherent sources, such as monochromatic and white LEDs, see Light Shaping Toolbox

The Diffractive Optics Toolbox can import a desired pattern and then develop a phase function using Interative Fourier Transform Algorithm (IFTA).

To create a quantized, multi-level physical structure from the smooth phase function, Thin Element Approximation (TEA)is used.

Then the Parameter Run in the Diffractive Optics Toolbox is used to optimize the final structure for a multi-level diffractive lens or a metalens. Within the Parameter Run, a wide range of physical parameters and merit fuctions can be selected. Minimum and maximum ranges for each parameter can be specified, as well as the number of steps to vary in each range. Some parameters can be varied linearly, while others varied randomly. Parameter runs can be programmed to run automatically using C# program snippets. For more information on programming, click on the following link: Programming and customization ...

A Zemax phase function can also be imported by the VirtualLab Diffractive Optics Toolbox, so that a multi-level diffractive lens or metalens can be designed and optimized, as described above.

The Diffractive Optics Toolbox exports the resulting DOE structure to fabrication files in several formats, including: GDSII, CIF, Bitmap, ASCII/.csv, Point-Cloud, STL.

Spatial light modulators for light shaping can also be modeled and simulated by VirtualLab. A desired pattern is imported by the Diffractive Optics Toolbox to create a phase function.

The phase mask is then used by the Starter Toolbox to model the entire optical system, including the SLM.

A practical feature of the Diffractive Optics Toolbox is the available session editor (wizard) which guides users through the workflow for diffractive optical design and simulation.

Although the Diffractive Optics Toolbox can operate independently, it is most often used with the VirtualLab Starter Toolbox, because the Starter Toolbox can include all the optical elements in a light path, in addition to the DOE or SLM. The Starter Toolbox can include sources, all optical elements, detectors and analyzers. It includes parametric optimization for the entire optical system, such as distances, positions, sizes, angles, wavelengths, and many more parameters.

    shaping by cells arrays

        mirror cells array

The VirtualLab Light Shaping Toolbox program is intended for beam shaping and homogenization of partially coherent sources, such as monochromatic and white LEDs. The simulation and design includes diffraction, interference and partial coherence effects.

It is often used for illumination systems.

The Light Shaping Toolbox creates an array of gratings, prisms or mirrors (first-surface reflecting prisms) for multichannel deflection of a beam to desired angles for pattern generation or beam homogenization.

Grating cells arrays, prism cells arrays and mirror cells arrays can be configured by number of cells and cell size.

Grating cells arrays can also be configured by grating period, rotation angle and lateral shift (phase shift to avoid pattern/pixel effects). The first diffraction order is used for generating the target pattern, but the physical optics analysis is done for all user-specified orders.

Prism cells arrays and mirror cells arrays can also be configured by tilt angle, rotation angle and and offset height (phase shift to avoid pattern/pixel effects).

Cells array configuration settings (such as: period, rotation angle, grating lateral shift, prism offset height) can be fixed or randomly varied over user-specified ranges.

The choice of grating cells arrays, prism cells arrays, or mirror cells arrays depends partially on the amount of wavelength dispersion in the resulting image. Mirror cells arrays eliminate dispersion.

Cells array data can be exported to ASCII files, and also to GDSII files for binary mask fabrication.

Although the Light Shaping Toolbox can operate independently, it is most often used with the VirtualLab Starter Toolbox, because the Starter Toolbox can include all the optical elements in a light path, in addition to the cells arrays. The Starter Toolbox can include sources, all optical elements, detectors and analyzers. It includes parametric optimization for the entire optical system, such as distances, positions, sizes, angles, wavelengths, and many more parameters.

          2D grating

          3D grating

volume holographic grating

          grating stacks

The VirtualLab Grating Toolbox program is for rigorous design, optimization and simulation of periodic structures. It uses fully vectorial Fourier Modal Method (FMM), which is the same as Rigorous Coupled Wave Analysis (RCWA).

The Grating Order Analyzer in the VirtualLab Grating Toolbox shows Rayleigh coefficients and diffraction efficiencies of grating orders. Diffraction efficiencies can be shown graphically or in a table. Graphical coordinates can be specified in spherical angles, cartesian angles, wave vector components or positions.

Diffraction efficiencies can be shown for all orders, a selected range of orders, or only diffraction efficiencies above a specified threshold.

Rayleigh coefficients can be shown for Ex, Ey, Ez, TE or TM.

In addition to diffraction efficiencies, other features include: near field and far field distributions, reflectance, transmittance, absorption, field inside grating and polarization of diffraction orders

The Polarization Analyzer in the Grating Toolbox allows the evaluation of the wavelengths and angular dependency of polarizing gratings.

Parametric optimization can be used to determine performance, such as: grating efficiency vs wavelength or efficiency uniformity for a specified spectral range.

Mulitple parameters can be varied, such as: grating period, modulation depth, slit width, incident angles, wavelength ranges, and polarization.

Also, multiple merit functions can be varied, such as: efficiency in a particular direction or polarization contrast.

The Grating Toolbox uses a stack concept to configure grating structures. A stack can be a sequence of individual interfaces, or it can be a medium, such as a volume grating medium. Coatings can be added as needed.

Measured and programmable height profiles can be included in grating stacks. Programmable index of refraction distribution can also be used.

The Grating Toolbox includes catalogs of interface types, materials and coatings. You can also create or import other items to the catalogs for future use.

When used along with the Starter Toolbox program, VirtualLab is an integrated software suite of programs for modeling all the microscale and macroscale components in an optical system.

        ulrashort pulse

          ultrashort pulse

        ultrashort pulse

pulse stretching & compression

The VirtualLab Fusion Starter Toolbox can simulate pulse propagation through optical systems, including: lenses, gratings and micro-optical elements.

In addition to simulating propagation through various mediums, the Starter Toolbox can model pulse shaping and pulse stretching and compression.

Pulses are represented by sets of harmonic fields. Fast Physical Optics in VirtualLab Fusion provides, fully vectorial pulse information.

A Pulse Evaluation Detector can be placed in the light path to show the pulse shape. The detector generates pulse information for the Ex, Ey and Ez components of the electromagnetic field. Spectral and temporal pulse profiles are shown, taking into account broadening due to material dispersion and angular dispersion.

The evaluation can be in 1D, 2D and 3D, and 3D pulse information can be converted into an animation.

Ideal pulse shaping can be modeled by changing parameters in the Ideal Pulse Shaper Editor and by a programmable component.

Using frequency filters, temporal pulse shaping can be modeled both with and without spatio-temporal coupling.

Using a programmable component spectral amplitude or spectral phase can be modulated. Spatial dispersion, group delay, and group delay dispersion can be switched on or off to include or exclude spatio-temporal coupling and temporal chirp.

Pulse front tilt can be shown in the spectral and temporal domains.

Pulse stretching and compression can also be modeled in VirtualLab Fusion. Ideal pulse stretchers and compressors are modeled by transmission functions to introduce wavelength-dependent phase shifts. The phase shifts are obtained by the optical paths of the light through the stretcher and the compressor.

A programmable component is used to define parameters, such as: the stretcher input.

The Parameter Run in VirtualLab Fusion can be used to investigate and optimize pulses. Angles, distances, lateral offsets, and detector parameters can be varied over a minimum/maximum range of user-defined values. Parameters can be varied individually or in combinations. The parameters can be varied in four different ways: standard, programmed, scanning and random (Monte Carlo). The results can be exported to Excel.

To rigorously design gratings, such as gratings in pulse stretchers and compressors, the VirtualLab Fusion Grating Toolbox program is needed.

  stable and unstable resonators

            ring resonator

    laser resonator components

The VirtualLab Laser Resonator Toolbox is for the design and simulation of continuous-wave solid-state lasers, both 3-level and four-level.

It models fundamental and higher order eigenmodes of stable, unstable and ring resonators. Output power and beam quality (M²) are calculated, taking into account thermal lensing, birefringence, and nonlinear gain saturation.

Fully-vectorial formulation of the Fox and Li method is combined with a vectorial beam propagation method (vBPM), enabling calculation of the dominant transversal eigenmode of realistic cw solid-state lasers. The vBPM is used to simulate light propagation through the active medium including the effects of thermal lensing, stress-induced birefringence and nonlinear gain saturation.

Intracavity components, such as: mirrors, lenses, polarizers, apertures, and index-modulated media can be included.

When used along with the VirtualLab Starter Toolbox program, optical components outside the resonator can also be included in the simulation, and the entire optical system can be optimized, using the Parameter Run.

Rigorous analysis of components, such as gratings and diffractive shaping optics can done with the VirtualLab Grating Toolbox and Diffractive Optics Toolbox programs.

      custom programming

    programmable interface

  programmable light source

        snippet program

      source code editor

As VirtualLab users gain experience, customization is often helpful to meet specific requirements. There are two types of custom programming in VirtualLab, snippets and modules.

Snippets are used to customize items, functions and processes that are included in VirtualLab. They are programmed in C#.

Examples of snippet programming are: programmed light sources, interfaces, mediums, materials, components and detectors, as well as transmission functions and programmable height profiles.

Customized items can be saved in catalogs for future use.

Parameter Runs can also be configured and automated, using C# program snippets. A snippet can specify which parameters to vary, minimum and maximum ranges for each parameter, and number of steps within each range. Some parameters can be programmed to vary linearly, while others vary randomly. Programmed Parameter Runs allow a great amount of flexibility for optimization and tolerancing.

Modules are another way to customize VirtualLab. They are used for creating new mathematical routines and analysis methods beyond those included in VirtualLab. Modules are programmed in C# or Visual Basic. Two available examples of VirtualLab modules are: Computing the Standard Deviation between Two Harmonic Fields, and Programming a Module that Smooths the Edges of a Structure. Ask to see these examples.

VirtualLab includes a source code editor for C# programming. To simplify setting up complex parameters, a graphical user interface is also available within the editor.

Snippets and modules can reference methods from the VirtualLab.Programming.dll such as: detectors and functionality to extract underlying complex fields, and rigorous Fourier Modal Method calculations for general incidence fields.

Snippets and modules can call functions from external DLLs, including .NET DLLs and C++ DLLs

MATLAB functions can be used within VirtualLab snippets and modules. By compiling MATLAB code as a .NET DLL, it can be called from within a snippet or module.

Batch operations can be programmed to control VirtualLab from command lines instead of the regular graphical user interface. The results can be exported to xml files.

Programming information is available in the user manual and a program reference. Also, many examples and tutorials of VirtualLab programming are available, such as: programmable light sources, detectors, materials, mediums and many more. Contact HMS Technology Sales to receive this information.