Learning Forum

[handon]

Hello,

I imported the measured refractive index & extinction coefficient into FDTD and have tried to fit the n, k parameters.

The refractive index was easy to fit parameters.
However, the extinction coefficient was difficult to fit well. (the order of extinction coefficient is -5 ~ -6)
It is important for the simulation because I have to consider the parasitic absorption of the material.

How can I fit the absorption coefficient well?

I already read tips but they weren't helpful for me.

[Guilin Sun]

You may significantly increase the "imaginary weight" till the imaginary fits as expected. Sometimes it can be difficult to fit well for both parts, then you will need to choose. You may also specify fit range in order to improve the fitting. Please refer to this article Tips for improving the quality of optical material fits