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Help to debug the EME simulation setup.


    • vahram.voskerchyan3

      I am trying to calculate how the duty cycle of the grating affects the reflection and transmission profiles. And I am getting wrong results. The attached code is the EME setup, please help me to identify what is wrong with the simulation.  I am trying to sweep the duty cycle of the grating for 1000 periods and plot the transmission versus the duty cycle sweep. I have selected the conserve energy method and when doing so I can see that maximum peak is at 0.5 duty cycle.  But when turning off the conserve energy I get a plot like this. I want to do make passive because I want to see at which length the transmission becomes 0.

      And when the conservation of energy is setup the plot is as follows. 

      I was expecting to see a similar plot with the "make passive" option on. 

      I have tried mode convergence sweep to see where the profile gets stable, I tried different meshings, and setting up cells differently. But the results are still confusing. Can you please help me to identify the problem ?

      I have also attached the script. In the link below.



    • Guilin Sun
      Ansys Employee

      Unfortunatelt we are not allowed to download any customer files from this forum.

      For periodic simulation, please use "conserve energy". This is because, any minor change in S can result in huge difference when many periods are used. as you can see, (S+ds)^N so when N is large the error will be amplified significantly.

      On the other hand, the convergence testing can be challenge:

      Understanding EME error diagnostics

      Convergence Testing - Error Diagnostics - Method for Using Diagnostics

      EME Convergence Testing - An Intuitive Approach

      Convergence testing process for EME simulations

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