How to realize the change of refractive index with space and time in plugin material

Continuing the discussion from How to realize the change of refractive index with space and time in plugin material:Who could give a solution for me about the spatial variation in base material

Hi @phd.wangbo,

I briefly mentioned how to do this in our previous discussion, but we can go into more details under this thread. This is what I wrote:

“Regarding the spatial variation of the index, you can use the Import object - Spatial (n,k) data method for the base material. You just need to create a text file (with the appropriate formatting, described in the link above) that contains the material index evaluated at different points in the structure.”

Please take a look at the KB page and let me know if you have any questions.

I’m trying to do something similar to this. However, I have a question, what is the difference between writing epsilon as two function each of which depends on single parameter (i.e. position and time) and writing it as a one whole function containing two parameters? How can lumerical deal with each of the two cases?

Waiting for your reply.