Learning Forum

[schinta3]

[Guilin Sun]

It seems you deleted the question. Maybe you have found the solution. But I will post some references here

• Material Explorer
  • Modifying the Material Fits
• Material Permittivity Models
  • Creating Sampled Data Materials
  • (n,k) Material Model
  • Analytic Material Model
  • Material Conductivity Models
• Anisotropic Materials
  
  • LC Rotation
  • Permittivity Rotation
  • Matrix Transformation
  • Grid Attribute Tips
• Advanced Material Models
• Flexible Material Plugin Framework

[schinta3]

Hello,

 

I apologize. I was wondering what 'rules' are enforced when the FDTD material model fits to sampled 3D data for an optical model. For example, does it force Kramers Kronig consistency across the real/imaginary? Or are there other rules?

 

 

[Guilin Sun]

In FDTD, yes. It must be causal.

[schinta3]

Hello,

is it possible to add an arbitrary material data (sampled n,k data) that may not be Kramers Kronig consistent?

[Guilin Sun]

The built-in material mode obeys the Kramers Kronig causality. However, you could for example set the imaginary part to be zero, and refit it. There might be some difference between the original and newly set model. So you need to confirm the effectiveness.

If the new model modifies the real part too much, you may consider to sweep wavelength with the fixed real part, provided that the raw data is smooth, in order to get smooth result. You may also fix the mesh size by enforcing this:

with the minimum wavelength.