Topics related to Lumerical and more

Reflection index

    • teddie smith

      As far as I know, there is a parameter called 'reflection index' that relates to the reflection and transmission of a material surface. I wonder what this value is set to in FDTD.

    • Guilin Sun
      Ansys Employee


      Do you mean how to set the material property the refractive index in FDTD?

      If so, there are mainly two methods to assign the refractive index:

      1: if it is a fixed value, or diagonal anisotropic, you can directly assign it:

      2: use the material database. For example, Silicon:


      Please refer to


      If you want to calculate the refractive index from reflectance and transmitance you can by whatever the software/script you have at hand. Lumerical software only needs the refractive index or permittivity for simulation. You can import it


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