FDTD Solutions 3.1
Sophisticated scripting language
FDTD Solutions now supports a sophisticated scripting language, which can be used to automate simulation and analysis, while allow for more complicated analysis to be performed.
Interface with Breault Research Organization’s ray-tracing package ASAP
In Release 3.1, FDTD Solutions can now exchange electric-field information with BRO’s ASAP 2005, allowing designers to exchange field information between the macroscale optical modeling environment of ASAP with the microscale optical modeling environment of FDTD Solutions.
Enhanced specification of source parameters
It is now easier to visualize the frequency- and time-domain profiles of the sources used in your simulation. Within the source edit windows, plots now update to show the frequency content of your source and the temporal profile of the injected pulse.
Bloch boundary conditions
FDTD Solutions now supports Bloch boundary conditions.
Improved technical specifications
Major enhancements to the way in which sources are injected have resulted in marked improvements in the technical specifications of the product.
Physical object rotation
For increased flexibility in creating physical structures, physical primitives can now be rotated in both two and three dimensions.
Surfaces of revolution
The custom primitive, which uses parameterized equations to define it surface, can be either extruded in one dimension, or rotated about an axis to create a cylindrically-symmetric surface of revolution.
Radiation sources can now be designated as ‘standard’ sources with a constant optical carrier frequency, or ‘broadband’ sources which have a chirped optical carrier (i.e. the carrier frequency varies under the pulse envelope). The new broadband source allows you to measure the system response across very wide frequency ranges (i.e. 200 to 1000 THz, or across the entire near-UV visible and near-IR part of the spectrum).
Improved 3D visualization
The perspective view of the 3D layout editor, located in the upper right-hand panel, now supports zoomed views and view rotation.
FDTD Solutions 3.2
Import images to create physical structures
FDTD Solutions can now import images, such as SEM images, to create two and three dimensional structures.
Diffraction limited spots from thin lens structures
Fully-vectorial, tightly focussed beam sources coming from thin lens structures are now available in FDTD Solutions.
Grating functions to calculate the strengths of each order of transmission and reflections gratings
New script functions allow you to calculate the strengths of grating orders for arbitrary input angles.
FDTD Solutions can now handle anisotropic materials.
Improved materials database interface
The new materials database interface and scripting commands makes it easier to verify your material settings.
FDTD Solutions 4.0
FDTD Solutions has been optimized to speed up simulations and use less memory. Version 4.0 typically runs from four to ten times faster than previous versions for the same simulations and uses about half the memory! The actual speedup that you achieve will depend on your simulation settings and specific computer hardware.
There is a new surface object primitive that allows conic shapes, polynomial surfaces, as well as any custom surface defined by an analytic equation of the form z = f(x,y).
Smoother Far Field Projections
When projecting to far fields, there is often an unphysical ripple due to clipping of the small, but non-zero fields at the edges of the simulation. These ripples can be removed by appropriate filtering, making it easier to see the distribution of light in the far field.
FDTD Solutions 5.0
FDTD Solutions now supports a non-uniform, or graded, mesh. This can dramatically increase speed and accuracy for many problems, as well as reducing the memory requirements.
Polygon and triangle primitives
FDTD Solutions now supports extruded N-sided polygons and triangles.
Quadrics and Infinipath interconnects
FDTD Solutions now supports even more high performance computing (HPC) networking interconnects, including Quadrics and Infinipath. Please see the Installation Manual for details on configuring your installation for your HPC hardware.
Native support for the Windows x64 platform
FDTD Solutions has added a full Windows x64 application to the current Windows 32-bit and Linux 32- and 64-bit versions. For details on installing the correct version for your hardware and operating system (OS), please see the Installation Manuals.
Easier installation of parallel FDTD Solutions
Get your parallel FDTD Solutions up and running faster! The easy installation lets you immediately take full advantage of your multi-core and multiprocessor systems, as well as larger scale clusters.
Each physical structure primitive can control its own mesh order (priority), making it easier to draw complex, overlapping structures. Advanced users can now store the mesh from previous simulations and re-use it to save meshing time.
Faster drawing modes for all primitives
All physical structure primitives now support wireframe, vertex wireframe and pixel drawing modes which can make the manipulation of large numbers of primitives more convenient in the Layout Editor.
Simulation auto shutoff
Simulations can detect when the electromagnetic fields have decayed and automatically terminate the simulation early.
Improved movie monitors
The movie monitors now support mpeg movies of and well as the usual electromagnetic field components. The user can now choose the final movie resolution in pixels for better viewing.
FDTD Solutions 5.1
FDTD Solutions can now import GDSII files. The GDSII files use a standard data format to store 2D geometric data. These files can be imported to create complex multi-layered structures in your simulations.
Improved figure windows
Control over the figure window color map has been expanded. The color map limits can now be adjusted. This is useful when creating several images with a consistent color map. A grey scale color map is also available, which is useful when creating figures to be printed in black and white.
n and k import
The import structure, used to import physical structure data from a file, has been expanded. Refractive index (n and k) data as a function of space (3D) can be imported from a file or matrix.
Set view and orbit
The setview command gives the user complete control over the perspective view window. The orbit command will view the current simulation objects in an elliptical orbit. This can make viewing the simulation objects easier. Movies of the orbits can also be created.
The import structure, used to import physical structure data from a file, has been expanded. Surface data of the form y = f(x) or z = f(x,y) can be imported from a file or matrix. This data can be generated from an analytic formula or from an experimental source such as an AFM.
Windows Vista support
Windows Vista has been added to the list of supported systems. For details on installing the correct version for your hardware and operating system (OS), please see the Installation Manuals.
FDTD Solutions 6.0
Multi coefficient material model
In the past, FDTD Solutions supported single Plasma, Lorentz, Debye or combinations of these dispersive models. FDTD Solutions 6 has a new generalized multi-coefficient model that allows more complicated data to be fit. The accuracy of the model can be controlled with the number of coefficients. More coefficients will give a better fit to experimental data, but at the expense of more memory and longer simulation times.
This model is only available when using the Sampled data material definition. The coefficients are automatically calculated from the sampled material data over the source bandwidth. See the chapter on the Material database for details.
Auto fitting of experimental data
The Sampled data material definition (for importing experimental data) uses an automatic fitting routine to calculate broadband model parameters from experimental data. This makes importing experimental data much easier, since manually calculating model parameters can be very difficult. See Material database for more information.
Improved material database GUI
The Material Database interface has been completely redesigned and simplified. The Database provides an interface to modify the properties of existing materials and to add new materials. The Material Explorer is used to view the index/permittivity profile of material in the database. See the Material databasechapter for more information.
Expanded list of material data
The number of materials included in the Material Database has been increased. Co, Cr, Cu, Ge, In, Ni, Pt, Ti, W, AlN, GaAs, H20 are some of the new materials. The frequency range of the data has also been expanded. Most materials have data at least from deep UV to far infrared.
The Spectral averaging feature of Power and Profile monitors calculates the incoherent spectral average of the electromagnetic fields or the Poynting vector as the simulation runs. The technique is much more efficient than measuring many frequencies and averaging after the simulation.
Two types of averaging are available. Total spectral averaging uses the source input spectrum as the weighting function. This is most useful when the source spectrum of the simulation matches the actual illumination conditions. Partial spectral averaging uses a Lorentzian weighting function multiplied by the source spectrum. Partial spectral averaging is useful to extract the average response of the system to a variety of different illumination conditions from a single simulation.
See the Spectral averaging section of the Units and Normalization chapter for more details.
More far field analysis
A number of new far field projection and grating script functions have been added. Three of the new functions are described here. For more information, see the far field function section of the Reference Guide: Near to far field projections.
The farfield3dintegrate function makes integrating portions of the far field much easier.
The farfieldspherical function converts direction cosine units (returned from the far field projection functions) into more familiar spherical coordinates.
The gratingvector function can be used to study the polarization of grating orders of periodic structures.
The entire Graphical User Interface has been updated. It is now possible to undock individual sub-windows from the main application. This can be very helpful when trying to make one sub-window very large. Another new feature is the ability to show/hide and rearrange toolbars.
User defined source signals
The source time signal is normally generated by FDTD Solutions based on the frequency range specified by the user. While the automatically generated pulse is usually appropriate, there are some simulations where a custom source time signal is desirable. FDTD Solutions 6.0 now supports user defined source time signals. See the script command setsourcesignal for more information.
Shorter source pulses
FDTD Solutions 6.0 uses a new algorithm to generate the source time pulse from the frequency range specified by the user. The new algorithm generates a much shorter time pulse, while still ensuring that most of the pulse energy is contained within the frequencies of interest.
The total simulation time of many simulations is dominated by the source pulse length. These simulations will experience a significant speedup because of the shorter pulse. Simulations with resonant structures, where the total simulation time is not dominated by the source pulse length, will not experience this speedup.
FDTD Solutions now supports Unicode file names and file paths. This allows users to work in directories and save simulation files with names that include characters from Japanese, Chinese, or other languages that are supported by the Unicode format.
FDTD Solutions 6.5
The ability to group structures is one of the main new features in FDTD 6.5. Groups can be moved, rotated and copied as a single object. In addition to simple grouping, it is possible to create parameterized group-objects by adding script code to the group.
For example, it is possible to create a Photonic Crystal Array group with a Pitch input parameter. When the Pitch parameter is changed, all objects in the group will automatically move to the appropriate position. For an example of how to create and use a group see the pc micro cavity tutorial in the getting started section.
Analysis (monitor) groups
The ability to group monitors into Analysis groups is one of the main new features in FDTD 6.5. Groups can be moved and copied as a single object. In addition to simple grouping, it is possible to create parameterized group-objects by adding script code to the group.
For example, it is possible to create a Scattering Cross-section Analysis group. The group is composed of 4 monitors that form a box around the structure. One associated script adjusts the monitor positions as defined by the input parameters. A second script calculates the scattering cross-section from the monitor data. This analysis group is set up in the monitors section of the Getting Started nanowire resonance tutorial. A second analysis group example can be found in the pc micro cavity tutorial.
Object tree browser
The object tree browser provides an alternate view of objects within a simulation. It is especially useful for complicated simulations with many overlapping objects. In such cases, it is much easier to select objects from the tree view than directly in the graphical view ports. It also makes selecting objects within groups possible. For more information, see the layout editor tabs and object tree section of the Layout editor chapter.
Built in script file editor
The Script file editor allows you to create, edit, and run script files directly from within FDTD Solutions, rather than using another text editor like Notepad. Syntax highlighting makes it easier to read, write and debug script files. The Run Script button makes running the script quick and easy. For more information, see the script prompt and script file editor page in the Layout editor section.
Script syntax highlighting
The Script File Editor and Script Prompt have syntax highlighting to make the commands easier to read, write and debug. Comments are green, strings are red, and loop/control statements are blue.
Copy and Paste
FDTD Solutions now supports Copy and Paste operations. This allows you to copy (Ctrl-C) a group of objects from one simulation and paste (Ctrl-V) a copy of those objects into a different simulation. This is especially useful with the new structure and analysis groups.
Dipole radiated power calculation
The dipolepower script command returns the actual power radiated by a dipole source. This greatly simplifies calculations that require knowledge of the radiated power, such as enhancement and efficiency measurements.
New Mode Source script commands
The updatesourcemode script command automatically updates the mode profile of the MODE source. This makes it much easier to automate some types of parameter sweeps.
The get script command now returns the mode profile stored in the MODE source, in addition to the other object properties.
The clearsourcedata script command clears the mode profile from the MODE Source.
Other new script commands
The following script functions were added in FDTD Solutions 6.5. For more information, see the function description in the scripting section of the Reference Guide.
system, almostequal, not, square brackets, single quotes, format, updatesourcemode, clearsourcedata, addstructuregroup, addanalysisgroup, adduserprop, addtogroup, getmaterial, havedata, layoutmode, sourceintensity, sourceintensity_avg, sourceintensity_pavg, dipolepower, runanalysis, runwizard, wizardgetdata, setplot.
Online Help search bar
The Online Help search toolbar provides easy access to the FDTD Solutions Online Help website. The toolbar will open your default web browser and search the Online Help for the requested term. This is particularly useful when searching for script function syntax. For more information, see the toolbars page in the layout editor section.
Simplified licensing: The USB hardware keys now contain much of the licensing information (expiry dates, quotas). In many cases, license files are no longer required.
Matlab script integration: FDTD Solutions automatically detects MATLAB. The MATLAB script integration step of the FDTD installation has been removed.
MATLAB is a registered trademark of The Mathworks, Inc.
Improved material fits
The fitting functions used to generate material models from Sampled data materials have been improved to give more control over the fits that can be generated. For example, you can specify a custom wavelength range or force the fit to give priority to the real or imaginary part of the permittivity.
FDTD Solutions 7.0
Optimization is a key component of FDTD Solutions 7.0 Optimization is important when there is a large parameter space, where simple parameter sweeps require too many simulations to be practical. Prior to FDTD 7.0, it was possible to implement your own optimization algorithms via the scripting language, but this can be a difficult task, due to the complexity of optimization algorithms. FDTD 7.0 includes a new optimization feature which provides a graphical interface to a built in Particle Swarm based optimization algorithm. It is also possible to create your own custom optimization algorithms within this graphical optimization feature.
Achieve higher accuracy for a given mesh size with conformal meshing. The conformal meshing technique can resolve interfaces to much higher precision than the standard staircase meshing, making it an ideal method to solve structures with thin layers, curved surfaces and high index contrast materials, such as surface plasmon or silicon on insulator waveguides.
Parameter sweeps are a very common task. Prior to FDTD 7.0, creating parameter sweeps required the scripting language. One of the major new features in FDTD 7 is the ability to do parameter sweeps in a completely graphical way, without the use of the scripting language.
A library of complex structure groups and analysis objects have been incorporated into the graphical CAD environment. In the past, many of these objects were available via the Online Help, but making them available directly from within the product is much more efficient. The new object library includes complex structure groups like waveguide components, randomized clouds of particles, photonic crystal arrays, etc. It also includes analysis objects like power transmission boxes, cavity Q calculators, S-parameter monitors, etc.
Mac OS X support
Mac OS X v10.5 Leopard and above has been added to the list of supported systems.
Windows 7 support
Windows 7 has been added to the list of supported systems.
Simplified installation and licensing
The Portable and Floating license options have been merged into a single licensing option. It is no longer necessary to install the stand-alone Lumerical License Manager. All licensing information (quotas, expiry dates, etc) can now be stored directly on the USB hardware key. The behavior of the key (portable or floating) can be changed at any time without assistance from Lumerical.
More flexible PML configuration options
PML boundaries are intended to absorb all incident light, with zero reflection. In practice, there is always some reflection. This reflection can be minimized by using more PML layers, although this makes the simulation run slower. It is now possible to specify the desired PML reflection directly, rather than having to specify the number of PML layers.
PML boundaries perform best when the surrounding structures extend completely through the boundary condition region. Many users are unaware of this issue, making it a common setup mistake. In FDTD 7, the default behavior is to automatically extend the material properties through the PML boundaries, even if they were not drawn that way. This should result in better PML performance (absorption) for these users.
Improved GDSII import
The GDSII file import functionality has been improved. GDSII operation scale, rotate, flip are now supported. Path types 0 and 2 are now supported.
Analytic material model
The analytic material model allows the user to enter an equation for the real and imaginary part of the permittivity or refractive index which can depend on the predefined variables listed below. However, it is important to remember that the specified equations are not used directly in the simulation. An FDTD material model must still be generated, much like the Sampled data material model. It’s important to check the FDTD model with the Material Explorer before running a simulation.
Other new script commands
The following script functions were added in FDTD Solutions 7.0. For more information, see the function description in the scripting section of the Reference Guide.
eval, getglobalsource, getglobalmonitor, setglobalsource, setglobalmonitor, groupscope, getsweepdata, clearanalysis, addgroup, polar, meshgrid4d, substring, findstring, replace, replacestring, polyarea, centroid, polyintersect, inpoly, polygrow, polyand, polyor, polyxor, lineintersect, linecross
FDTD Solutions 7.5
FDTD 7.5 provides a simple way to run multiple simulations at the same time.
For example, suppose you have 30 simulations from an optimization or parameter sweep task. In the past, each of the 30 simulations would run consecutively on the local computer. (It was also possible for the user to manually distribute the jobs in some other manner.) With FDTD 7.5, the jobs can be automatically sent to several computers in your local network. If there are three computers in the network, FDTD can run three concurrent simulations (one on each computer), reducing the time to complete the sweep by a factor of 3. Extra FDTD simulation engine licenses will be required to run additional simultaneous simulations.
Movie monitors in parallel simulations
Movie monitors now work in parallel (multi-process) simulations. In previous versions, movie monitors only worked when the simulation was run in single processor mode.
Other new script commands
The following script functions were added in FDTD Solutions 7.5. For more information, see the function description in the scripting section of the Reference Guide.
runsweep addjob, runjobs, clearjobs
FDTD Solutions 8.0
User-defined material models
Users now have the ability to create plugin materials and directly modify the update equations. This will allow for arbitrary nonlinear materials, negative index materials and many other forms of electric and magnetic field updates. Please see the User-defined models 2 section of the Reference Guide for more detail.
In addition, the following new material models have been added to the Material database 1 (and more material models will be introduced in the future):
, materials: users can now specify the
and terms for nonlinear simulations. An arbitrary dispersive base material can also be specified, in which case the added polarization will be in addition to the polarization of any base material that is selected.
Paramagnetic materials: users can now specify both the Permittivity and Permeability to simulate magnetic materials.
A Raman Kerr model based on the references below. This can be used model the Raman effect in Silicon. Some examples include soliton propagation and four-wave mixing.
Goorjian and Taflove, Optics Letters, 1992, 180-182
Allen Taflove, Computational Electromagnetics: The Finite-Difference Time-Domain Method. Boston: Artech House, (2005)
A Four-Level, Two-Electron laser model based on the references below. This can be used to model gain and lasing dynamics.
Chang and Taflove, Optics Express, 2004, 3827-3833
Allen Taflove, Computational Electromagnetics: The Finite-Difference Time-Domain Method. Boston: Artech House, (2005)
Please see the Application Library for examples that use these new material models.
Non-diagonal anisotropic media
FDTD Solutions 8 supports the full 9 element permittivity tensor:
where summation over j is implied on the right hand side. The full anisotropy tensor can be written as
To define this tensor, users will start by specifying the diagonal elements of the tensor. Then, arbitrary rotations to this tensor can be applied through a Grid Attribute object to induce the correct rotation. Please see Anisotropic materials 1 for more information on how to define this tensor.
This new feature allows users to simulate magneto-optical effects, as well as arbitrary Liquid Crystals orientations.
Results manager and Visualizer
The Results Manager is a tool for analyzing simulation data. This includes a Results View window which displays all the results for the simulation object that is currently selected in the Object Tree. The Results Manager also includes a Script Workspace and a Script Favorites window, providing additional GUI-based functionalities. Note: “Script Favorites” has been removed since 2019B.
Also featured in FDTD Solutions 8 is a Visualizer, which significantly simplifies the process of visualizing simulation data. When used in conjunction, Results Manager and the Visualizer provide a very useful and intuitive way of analyzing and visualizing variables and results through the GUI, greatly reducing the need for scripting.
3D only user interface
FDTD Solutions 8 allows users to perform 2D and 3D simulations on the same 3D structure by defining 2D and 3D simulation regions in the same project file.
A 2 dimensional drawing mode is provided so that it is possible to work only with a 2 dimensional slice of the structure. The 2 dimensional drawing mode looks very similar to the 2 dimensional drawing environment from 2D FDTD or MODE 4.
Mode expansion monitors
FDTD Solutions 8 features new mode expansion monitors. These monitors allow users to expand an arbitrary field profile (from a monitor) into a specific mode (or a set of modes). For more information on this expansion calculation, and the results that are returned, see Mode Expansion Monitors 2.
The Mode Expansion monitor greatly facilitates the interoperability between FDTD Solutions and INTERCONNECT as it returns the S parameters, which can be imported into INTERCONNECT directly.
Rotatable mode sources
MODE sources can now be injected along an angled plane by setting the rotation angles (see Sources). Users should make sure to extend the waveguide/fiber through the PML boundaries, and make sure that the "extend structure through pml" property under Edit FDTD Simulation -> Advanced options is unselected.
Yield analysis tool
A new yield analysis tool is available in the Optimization and Sweeps window. The yield analysis tool gives users the ability to run extensive Monte Carlo analysis, sweeping across multiple parameters to assess statistical variations of circuit elements on overall circuit performance.
Material fitting improvements
The material fitting routine has been optimized to improve material fits for dispersive sampled materials with low losses.
Other new script commands
A number of script functions were added in FDTD Solutions 8, including:
. operator, addattribute, addparameter, eig, debug, getattribute, getparameter, getresult, getsweepresult, integrate2, matrixdataset, addmodeexpansion, mult, permute rectilineardataset, reshape, updatesourcemode, updatemodes, seteigensolver, geteigensolver, clearmodedata, lookupread, lookupwrite, lookupopen, lookupclose
Lumerical datasets are structured data objects that collect a set of related matrices into a single convenient object. See Dataset introduction 1 for more information.