Regress
Q: In which format should I put the spectra for Regress Pro ?

Regress Pro require the spectra in a simple textual format. You can look in the 'examples' directory to see how the format looks like. For ellipsometric spectra the format is the following:

SE PSI DELTA
AOI 75.7
SE 239.986 0.73023 -0.026679
SE 240.1 0.744085 -0.0293415
...

where AOI is the angle of incidence at which the spectra were taken. Then you have the line with the experimental data in with the wavelength, tan(psi) and cos(delta) in the given order. If the first line was "SE ALPHA BETA" then each line should report the wavelength, the alpha and beta value in the order.

For a reflectometry spectrum the format is the following:

Measured data written by ADAP
nm
uR 402.523800 0.000000 0.237728 0.010000
uR 405.837300 0.000000 0.253238 0.010000
...

The first line is just a comment, the second line indicate the units for the wavelength (only nm are supported). Then you have the experimental data with the wavelength and the reflectance. The value of 0.0 and 0.01 are required for compatibility reason but are otherwise ignored.