Fixed data sets are tables of the real and imaginary part of the dielectric function given in a certain spectral range. Most of the data are obtained from literature somehow (by typing in or scanning published table values or digitizing published curves). Some may have been obtained from more or less direct evaluation of measured spectra (like KKR analysis of reflectivity data or spectroscopic ellipsometry).

Importing external optical constant data into SCOUT

If you want to work with fixed data sets for optical constants you have to create an object of type 'Imported dielectric function' in the list of materials. Objects of this type have an Import command that is used to import optical constant data from text files. In addition you can import data from the workbook.

The import of n and k data from textfiles is explained in a step-by-step example. Getting data from the workbook is also explained below.

Comments on spectral ranges of different objects

If you import fixed data sets from the database and you use them for a computation, the spectral range of the spectrum to be computed may differ from that of the fixed data set. Like in all SCOUT objects linear interpolation is applied to obtain dielectric function values in between two specified spectral positions of the dielectric functin object. In case of extrapolation the dielectric function values of the closest specified spectral point are used – this means that you should avoid extrapolation unless the dielectric function is almost constant.