The following types of monitors are available in Lumerical's optical solvers.
Index monitors records the n and k value as a function of frequency/wavelength in a simulation. Index monitors are only available in two or three dimensions; there is no option for linear or point index monitors. In the future, the index monitor will be able to capture the time-evolution of the physical properties profile for nonlinear media.
These monitors provide time-domain information for field components over the course of the simulation. Time-domain monitors can consist of point, line, or area monitors to capture this information over different spatial extents within the FDTD simulation region. For the purposes of extracting line widths of resonant structures through Fourier analysis, point time monitors with a down sample time of 1 are sufficient.
Movie monitors capture a desired field component over the region spanned by the monitor for the duration of the simulation. Movie monitors are only available in the two dimensional variety (and only z-normal for propagator simulations). The resultant movies are saved with the same name as the monitor in the current working directory.
Frequency-domain field monitors collect CW, steady state EM field data in the frequency domain from an FDTD or varFDTD simulation.
Mode Expansion Monitors use overlap analysis to calculate the forward/backward propagating components of any mode of a waveguide or fiber at an arbitrary location in the simulation region. The Mode Expansion monitor facilitates the interoperability between FDTD and INTERCONNECT as it returns the S parameters, which can be imported into INTERCONNECT directly.
The global monitor options window is where the user can specify the range and resolution with which to measure frequency-domain information. These settings can be used by any of the frequency domain monitors by unchecking the 'override global monitor settings' check box in the monitor's General tab.