Database of refractive index of materials

SOPRA has kindly provided database for various materials. You can download from the website, by clicking “Download center” at the right hand top, and then click “N&K database” at the left menu. You will have to register before you can download. It’s free!

I also downloaded FreeSnell to query the database. Anyway the database is a textfile, you can open it without any other software. But the program “nk” provided by FreeSnell makes things easier.

Download the files and unzip it. You will need to change the $(prefix) variable from each Makefile to change to your preferred installation location. The installation steps is given in the link above. If you install on other directories, you will need to modify the script “nk” and specify the location of “scm”. After this you will be able to run nk.

Before querying database, you will need to add the files into the database. Look at this page on how to do it.

and from the manual:
$ nk co .3.um .5.um 1.3.eV
co: 1.218+2.11i 300.nm (4.13.eV) (33333.3.cm^-1)
co: 2.025+3.72i 500.nm (2.48.eV) (20000.cm^-1)
co: 3.85+4.77i (954.nm) 1.3.eV (10485.2.cm^-1)
$ nk Al 400.cm^-1
al: 75.77+1.7e+02i (25.0.um) (0.0496.eV) 400.cm^-1

The `–plot’ option creates an encapsulated PostScript graph of n and k/n for the material specified.

nk –plot co

NOTE: in order to plot you need to have “gv”.