Welcome to RefFIT homepage !

RefFIT is a compact interactive program for Windows 95, 98, NT, XP designed to fit optical spectra, such as reflectivity, transmission, ellipsometry etc. with the Drude-Lorentz and many other physically sensible models. It can be useful to physicists, material scientists, chemists and everyone else using optical techniques to analyze materials. With RefFIT you are able to fit several types of data simultaneously and monitor precisely what you are doing.

RefFIT is the only existing program which allows you to apply the Kramers-Kronig analysis not only to the normal-incidence reflection, but also transmission, grazing-incidence reflection, ellipsometry and other types of data, using a novel variational technique.

RefFIT has a built-in macro language to perform lengthy routines with a single mouse click.

The complete RefFIT manual is available.

You are welcome to try it and give me your comments and suggestions. Please, show it to your colleagues. I would also appreciate if you mention in your publications that you used RefFIT in the analysis.

You can download the latest version of the program. In order to install it on your computer, copy all the files from this archive to a separate directory, for instance, “C:\REFFIT”, keeping the directory structure. To start it, run “REFFIT.EXE”.

I wish you a successful fitting!

Alexey Kuzmenko, University of Geneva

Email: Alexey.Kuzmenko@unige.ch

Here are some screenshots of RefFIT (click to enlarge them):

Drude-Lorentz fitting of the  c-axis reflectivity spectrum of Bi2Sr2CaCu2O8 (Bi-2212)

Simultaneous fitting of reflectivity andtransmission spectra of La2-xSrxCuO4 (LSCO)

Simultaneous fitting of ellipsometric parameters (ψ,Δ) for 3 angles of incidence of a Pb(ZrTi)O3 film on a SrTiO3 substrate

Simultaneous fitting of FIR reflectivity, NIR-UV dielectric function and DC conductivity of CeIrIn5

Fitting of spectra of SrTiO3  from 10 to 30000 cm-1:
time- domain complex transmission in THz range, reflectivity and trasnmssion in the FIR and NIR and ellipsometry from NIR to UV

 

 

 

 

 

 

RefFIT developments:

23.02.2014

Fano-shaped and Tauc-Lorentz oscillator models are added

16.11.2010

Complex transmission phase of a slab sample can be calculated

22.10.2010

Magnetooptical model is extended to the Voigt geometry

31.08.2010

A powerful magnetooptical model is included, which involves the optical Hall effect and the associated Faraday and Kerr effect

10.04.2009

It is possible to save variational dielectric functions (VDFs) in a separate file

13.10.2008

Reflectance/Tranmittance/Ellipsometry measurements on multilayer samples with (possibly) suppressed Fabry-Perot effect can be modeled

04.04.2007

Reffit can calculate the absorption coefficient

27.03.2007

It is possible to limit the parameter values to an interval

10.10.2006

A model is added to fit reflectivity of a sample embedded into a medium (can be useful for experiments when a sample is in a liquid or in a pressure cell)

19.12.2005

A model of the electronic conductivity in the Marginal Fermi-liquid theory is added

21.09.2005

The possibility to fit the complex phase of the reflection and transmission is added, which is useful for the analysis of the spectra measured with time-domain THz spectrometers and BWO-based spectrometers

20.08.2005

A model for the electron-phonon interaction is introduced

19.06.2005

New model: “Optics of a plate sample”. Now the incoherence between multiple reflections is properly treated

17.03.2005

RefFIT can now calculate (and fit also!) the integrated spectral weight

10.11.2004

The possibility of a frequency-dependent magnetic permeability μ(ω)≠1 is added

02.08.2004

The factorized (TO-LO) model for the dielectric function is added

25.05.2004

This webpage was opened

27.03.2007

It is possible to limit the parameter values to an interval

10.10.2006

A model is added to fit reflectivity of a sample embedded into a medium (can be useful for experiments when a sample is in a liquid or in a pressure cell)

19.12.2005

A model of the electronic conductivity in the Marginal Fermi-liquid theory is added

21.09.2005

The possibility to fit the complex phase of the reflection and transmission is added, which is useful for the analysis of the spectra measured with time-domain THz spectrometers and BWO-based spectrometers

20.08.2005

A model for the electron-phonon interaction is introduced

19.06.2005

New model: “Optics of a plate sample”. Now the incoherence between multiple reflections is properly treated

17.03.2005

RefFIT can now calculate (and fit also!) the integrated spectral weight

10.11.2004

The possibility of a frequency-dependent magnetic permeability μ(ω)≠1 is added

02.08.2004

The factorized (TO-LO) model for the dielectric function is added

25.05.2004

This webpage was opened

 

 

Last updated: 31. 08.2010