Topics related to Lumerical and more

How to get phase from monitor in FDTD


    • Ziyao Zhang

      Dear sir/madam,

      I would like to ask how could I know the phase of modes transmitting in waveguide. I tried to find the phase information in mode expansion monitor, but the angle are always pi. I know if I use ports, I can konw the phase but my simulation needs plane wave source with different polarization, so I can not use ports (if there is a way to set polarization of plane wave in ports, it would be great). Looking forward to your reply!

      Yours sincerely,


    • Amrita Pati
      Ansys Employee

      Hi Ziyao,

      You should be able to get the phase from the mode expansion monitor. Sometimes, it is hard to get a sense of the absolute phase. In those cases, you can use a narrowband source with multiple frequency points and calculate the relative phase at each point with respect to the phase at central frequency to get more insights into how phase changes over the spectrum.

      This might be a useful reference, but the analysis group used in this work (grating_s_params) is applicable to periodic structures only:

      Ports are a combination of mode source, DFT monitor, and mode expansion monitor. So, you will not be able to inject plane waves into the waveguide using Ports.


Viewing 1 reply thread
  • You must be logged in to reply to this topic.