The direction of the blue arrow of the mode source does not change when I change the mode polarization


#1

I downloaded the ring_resonator.lms example file from the Getting Started example on this page:
http://docs.lumerical.com/en/index.html?pic_passive_getting_started_ring_resonator_mode1.html

From my understanding the direction of the blue arrow of the source shows the polarization direction of the electric field, but when I edited the source and selected a TE polarized mode, why doesn’t the direction of the blue arrow of the mode source change?


#2

When using the varFDTD solver, the polarization direction that is shown by the blue arrow indicates the polarization of the slab mode which is used in the effective index method to collapse the 3D simulation region into a 2D simulation with a set of effective indices.

If you intend to inject a TE mode instead of a TM mode, you need to first edit the varFDTD solver region and select the TM slab mode in the “Effective index” tab of the editor window, and you should see the direction of the source’s blue arrow change accordingly.