# Alpha term for Raman/Kerr in silicon

#1

The page that provides the information on the Chi3 Raman Kerr material model describes an alpha term that determines the relative weighting between the Kerr and Raman effects. The included references use α = 0.7 for silica; is it possible to find this value for silicon?

#2

It might be possible to find the alpha value for the material you want for the non-linear effects from the literature. In this KB example, we are use alpha=0.957 for silicon to simulate four wave mixing. For different material and different non-linear effects, you may need a different value of alpha. I will encourage you to do a literature search to see if you can find anything.
https://kb.lumerical.com/en/index.html?nonlinear_four_wave_mixing_fwm.html

#3

Thank you for the response,

I did do a literature research, of course, but silica seems to be the only material documented. Is there are reference for the 0.957 alpha on the example in the link?

Thanks again

#4

I believe this alpha value was used for demonstration purpose in this example. That said, I agree that it’s best to have a reference for this value. I did some search on the literature but no luck finding one for silicon.

#5

Thank you for your help. I will keep looking.