The types of monitors that can be added from the Monitors menu in varFDTD are the refractive
index, effective index, field time, movie, frequency domain field profile, frequency
domain field and power, and mode expansion monitors.
These are the same types of monitors as FDTD Solutions, plus the effective index monitor
which returns the material profile of the effective materials.
The effective index, field time, movie, and mode expansion monitors return data from the
2D simulation using the effective materials, so their geometries can only be set in the
x and y dimensions, and there is no the option for setting the position or span in the z-dimension.
The refractive index monitor can collect 3D data from the 3D geometry of the device.
The Frequency domain field profile, and frequency domain field and power monitors also support
collecting data in the Z-dimension.
For these monitors, they start by collecting 2D data from the simulation, but then can
then calculate the fields in the z-dimension by expanding the fields using the vertical
slab mode profile.
This will be demonstrated in the next unit.
Global monitor properties such as frequency range, and number of frequency points can
be set from global properties window.