Reply To: How to observe the phase of circularly polarized light

[Guilin Sun]

First, TFSF is a kind of "local" plane wave that inside the total field region (the source volume) it is a plane wave. Outside this region it is scattered field. When you set the TFSF area larger than the periodicity, it acts the same as a plane wave.

"the energy was stable around 0.003 and did not decay."  this indicates that either there is very strong resonance, or PML reflection. To confirm it is resonance, please use a time monitor and check the spectrum and see if there is any strong resonance within the interested bandwidth (the source band). If yes, you may need to increase the simulation time and reduce autoshutoff min as suggested previously. If the strong resonance is outside the source band, you can set the source in time domain: use longger pulse with larger offset.

Please use the definition of circular polarization to decompose the monitor field, if it has no higher order diffraction. You can use visualizer to get the farfield with assuming 10 periods. If it has higher order diffraction, you may need to use grating analysis to get the 0th order and do the decomposition.