Sure you do not need to simulate from metalens to its focus plane. you can use a monitor to record fields behind the metalens, so the simulation region is small. then use farfieldexact to get the fields at the focal plane: https://optics.ansys.com/hc/en-us/articles/360034930733-farfieldexact3d-Script-command
then you can analyze the field vectorial property with the resulting Ex,Ey ans Ez, not directly from the monitor.
You will need to analyze the polarizarion property of the fields.
You are navigating away from the AIS Discovery experience