This video is taken from the FDTD Learning Track on Ansys Innovation Courses.
The index monitor returns the refractive index or surface conductivity profile over space.
This monitor can have a 2D or 3D geometry, and by default, it returns the results at
1 frequency point only.
This monitor is most often used to check the structure that will be simulated to make sure
it has been set up correctly, and it is particularly useful if you have a complex structure made
of many different objects.
It is also helpful if you have multiple overlapping objects since it allows you to check which
object will be simulated in the overlapping region.
The object with lower mesh order will take priority.
More information about mesh order and meshing priority for overlapping objects can be found
in the page linked below.
Another case is if you have a structure with a refractive index which changes as a function
The index monitor allows you to check the resulting refractive index profile.
Most monitor data is only available after running the simulation.
However, the refractive index profile and surface conductivity can be previewed before
running the simulation.
A simulation region must be added before the index data preview can be generated.
Plotting the preview can be used as a quick way to check the structure before running
Data from index monitors are also used to calculate a variety of quantities such as
spatial power absorption and optical generation rates.
Common post-processing analysis functions can be found in the Analysis section of the
In the next unit, we’ll demonstrate how to set up an index monitor.