Photonics

Photonics

Topics related to Lumerical and more.

fdtd simulation

    • mauryaabha1602
      Subscriber

      I am trying to get the results of a paper but my results are not exactly same, although I put exact parameters like the dimension of structure (periodic), meshing, materials, source type(plane wave), and boundary conditions, I am still unable to generate the exact result, it differs a little bit from the original.

      any suggestion for this? how can I get the exact result?

    • Amrita Pati
      Ansys Employee

      Hi Abha,

      It could be due to a lot of reasons. It can be challenging to predict without looking at the simualtion file in detail. But this will give you a general idea: Ansys Insight: Why my simulation result is different from published paper or experiment?

      Regards,
      Amrita

    • mauryaabha1602
      Subscriber

      thank you for your reply.

      one more question, how can I decide the source location if the structure is periodic with a plane wave source? 

    • Amrita Pati
      Ansys Employee

      Hi Abha,

      If you are placing the source in a lossless medium, I think only the phase will be affected, other parameters like transmission won't be affected depending upon the location of the source. In general, it is advised to keep the source and the geometry lambda/2 distance away from the PML to avoid injection errors and also reflections from PML. What kind of PML profile are you using (the default is standard)? In peridic simulations, you can have diffrcation orders propagating at stepp angles to the PML boundaries, this can impact the performance of the PML. To reduce the effects, we generall recommend using the "steep angle" PML profile.

      Regards,
      Amrita

    • mauryaabha1602
      Subscriber

      I am using standard, and along with that, I want to inform you that I am using plane waves with periodic waves at normal incidence. 

      and also at the top of the structure  nanoparticle is there, 

      any suggestion now??

    • mauryaabha1602
      Subscriber

      what is lambda in the above answer?

       

    • Amrita Pati
      Ansys Employee

      Hi Abha,

      You can try the "steep" PML profile. Even though you have normal incidence, you could have diffration orders in different directions as it is a periodic geometry. Just to double check, you mention that there is a particle on top of the structure, is the whole geometry (including the particle) periodic? You can use periodic BCs with plane waves only when the geometry is periodic.

      lambda is the source wavelength. If you are using a wideband source then the best practice is to use the longest wavelength. 

      Would you be able to share a screenshot of the geometry? That will help me provide more specific information.

      Regards,
      Amrita

Viewing 6 reply threads
  • The topic ‘fdtd simulation’ is closed to new replies.