I'm interested in the absorption coefficient of silicon in the full range from 1 µm to 20 µm. Normally I only find data sets from 1 µm to 10 µm or in the visible range.
I had a look to the link and found the updated version (now up to 25 µm):
http://refractiveindex.info/
But I didn't find any information on this site about the extinction coefficient k in the range between 10 µm and 20 µm, only between 0.26 µm and 0.83 µm. Many thanks for your help.