Reply To: Query about the (n,k) data of gold for Terahertz region application

[Guilin Sun]

In the material database it has 3 sets of Au data:

you may choose the last one. The difference among them might be due to process technique and measurement method/accuracy in addition to the spectral range.

However if it does not meet your requirements you can find the refractive index somewhere and import:

Tips for using the (n,k) material model in FDTD