When Setting up a simulation file from scratch, you usually need to add materials, structures,
the simulation region, sources, and monitors.
The Main Toolbar of the layout editor contains the tools for adding these.
The Material Database can be opened by clicking the Materials button.
The database includes a default list of common materials, but you can also add new materials
based on a material model or by importing measured refractive index, permittivity, resistivity
or conductivity data.
It is possible to define spatially-varying materials, anisotropy and more.
See the Material properties section of this course, or the related link below this video
for information on adding new materials.
Basic structures can be added from the Structures menu.
More complex geometries can be imported from CAD files in GDSII or STL format, or from
images or surface height data over the position.
The Object Library also contains some pre-built structures, which can be opened from the Components
The setup of structures won’t be covered in detail in this course, but you can learn
more about it from the resources linked below this video.
The FDTD simulation region can be added from the Simulation button.
The simulation region is where the simulation geometry, simulation time, mesh settings,
and boundary conditions are specified.
Any objects that are not inside the simulation region will not be included in the simulation.
Mesh override regions can also be added from the Simulation button.
They are used to specify a finer mesh in regions where a higher resolution is needed, for example,
to resolve small geometric features.
More detail on the settings of the simulation region and mesh override regions is covered
in the FDTD solver region section of this course.
Sources are used to inject light into the simulation region.
Different sources inject different field profiles.
The available source types include basic sources like the plane wave, beam, and dipole, as
well as more advanced sources like the total-field scattered-field source, which allows you to
separate the simulation into a region which includes total fields and a region which only
includes fields scattered by a scattering object inside the source, and the import source,
which allows you to specify a custom field profile.
More information on source will be provided in the Optical sources section of the course.
Monitors are used to record simulation results.
The index monitor returns the refractive index profile over space.
The time monitor records the fields over time, and the movie monitor generates a movie of
the fields over time.
The frequency domain power and profile monitors return CW, steady-state transmission spectrum
and spatial field profiles.
The mode expansion monitor and ports are used to analyze the amount of power travelling
in a specific mode of a waveguide or fiber.
More information on monitors will be provided in the Monitors sources section of the course.
Analysis groups are containers that can be used to group structures, sources, and monitors
and return custom results.
Examples of analysis groups that are available in the Object Library include the transmission
box which returns the net power flowing through a box of monitors, the power absorption analysis
group which returns the spatial power absorption profile, and the Q analysis group which returns
the quality factor of a resonant cavity mode.
The analysis groups of the Object Library can be opened from the Analysis button.
You can also add a new empty analysis group from the Groups button.
Analysis methods, including information about analysis groups, will be discussed in the
Analyzing simulation results section.
The following unit will demonstrate the simulation setup for the nanohole array device.