As @kchow has mentioned, the spatial filter can be also defined based on its geometry.
When you press the ‘Calculate Modes’ button in the Eigensolver Analsys window, a set of monitors are automatically generated corresponding to the order of modes.
To calculate the integration of |E(x,y)|^2 over a triangular region, you need to take the following steps:
- Get the |E(x,y)|^2 data from the ‘modeXXX’ monitor (‘XXX’ corresponds to the mode order)
- Create a spatial filter, Filter(x,y), (‘1’ for the inside of the triangular region and ‘0’ for the outside)
- Multiply |E(x,y)|^2 and Filter(x,y), and then do the integration.
I have attached a simple simulation file containing a triangular waveguide [ FDE_tri_sf.lms (235.4 KB) ]
The definition of the triangle and the spatial filter are as follows:
After running the simulation, execute the script file [FDE_tri_sf.lsf (669 Bytes) ]
The script will generate two plots for the spatial filter and the |E|^2 filtered:
Finally, it will calculate the integration of |E|^2 over the triangular region.