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Modal Index calculations

(joined July 2020)
Participant

Hi Sir/Madam,
I have done 3D transverse mode calculations and found the number of Modes present and its modal index using the ADI Method.

Now my queries are,

1. Is the modal index we obtained using the above-mentioned simulation process is the effective refractive index of the mode in a designed waveguide?  
2. Apart from the Modal Index value, another value is also provided besides that, what is that value called? Please do find the attachment.
3. The comments in the Polarization is given as SVect TE (or TM), here what does SVect means?
4. Finally, is the modal index value is obtained by the depth-wise calculation of the “Designed Cladding-Core-Substrate” waveguide structure? Is it possible to do effective index calculation along the lateral direction?

Please do let me know if my questions are not clear.  
I am very new to the FDTD software, and it will be helpful with your positive reply.

Attachments:

Responses (2):

    • #67654
      Romala Sattibabu
      Participant

      Hi Sir/Madam,
      I have done 3D transverse mode calculations and found the number of Modes present and its modal index using the ADI Method.

      Now my queries are,

      1. Is the modal index we obtained using the above-mentioned simulation process is the effective refractive index of the mode in a designed waveguide?  
      2. Apart from the Modal Index value, another value is also provided besides that, what is that value called? Please do find the attachment.
      3. The comments in the Polarization is given as SVect TE (or TM), here what does SVect means?
      4. Finally, is the modal index value is obtained by the depth-wise calculation of the “Designed Cladding-Core-Substrate” waveguide structure? Is it possible to do effective index calculation along the lateral direction?

      Please do let me know if my questions are not clear.  
      I am very new to the FDTD software, and it will be helpful with your positive reply.

      Attachments:
    • #67687
      Profile Photo
      Scott Newman
      Moderator

      Hello Romala,

      let me address each of your points in turn:

      1. The modal index is the effective refractive index as seen by that mode in that structure.
      2. The other value you are referring to is the 0.00000 or the SVect TE? The 0.00000 is the imaginary potion of the modal index, in this case the modal index is entirely real. The SVect TE is the polarization of the mode.
      3. SVect indicates you ran a semi-vector simulation, if you had of run the Full vector it would be indicated by an FVect.
      4. You have performed a modal analysis over the area of the input plane as this is what will perform the injection. As it stands you can only have a Z-directed input plane and as such your modal analysis will be confined to the XY plane. We are working on introducing X and Y directed input planes with arbitrary tilt in the next release of the product.

      Scott

      • This reply was modified 3 months, 1 week ago by Scott Newman.
    • #67689
      Romala Sattibabu
      Participant

      Dear Sir,

      Thank you so much for your reply.
      It is really helped me a lot.

      Regards
      Sattibabu

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