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newAD2 - optical characterization software

Tutorial 1 - calculation of optical constants and other quantities

Although newAD2 is mainly intended for optical measurement fitting, it can be used without experimental input data to calculate optical constants using the implemented models and to model measurements. This first tutorial will show how to calculate optical constants of crystalline silicon using the built-in advanced dispersion model and how to model reflectance of half-infinite silicon wafer.
  1. Prepare a new directory including modelfile with media, functions and modeled functions sections. The media section defines the dispersion model for silicon (c-Si). The functions section contains the optical constants definitions for this model (dipsersion model calculate dielectric tensor) and modeled functions section contains definition and details (range and step) for the calculated optical constants.
    newAD2: model OTF
    
    media:
    cSi = c-Si
    
    functions:
    n,k-cSi = OC(cSi)
    
    modeled functions:
    n,k-cSi(E=0.001~10:1001:exp)
    
    Donwload modelfile
  2. Start newAD2gui and select the directory with prepared modelfile.
  3. Click on Model -> Load from File and select your modelfile. In case problems occur during modelfile loading, red error message will be shown in the bottom tray. In that case clicking on Messages button will show more details.
  4. Click Calculate to start calculation.
  5. After calculation finishes use grapherAD2 (Run Grapher button) to display calculated optical constants
  6. Besides optical constants, newAD2 can be also used to model other optical quantities. As an example we will model the reflectance of semi-infinite silicon substrate. The modelfile from first part will be used as a starting point, however some extension is needed. A new model for ambient is needed in media section (model Vacuum). A new boundary system definition (complex Yeh's boundary matrix M for vacuum/cSi interface) as well as style of measurement (Surface, which corresponds to Mueller matrix of the light reflected from semi-infinite media R). The corresponding function for reflectance measurements is M00, i.e. \(M_{00}\) component of Mueller matrix. Final modelfile can look like this: Donwload modelfile
  7. In the example the temperature dependence of quatities is demonstarated. Use grapher to check results. If you wan to export data, use the Output button. It will output all calculated quantities into a text file.
  8. After the calculation finishes, the program can be completely stopped using the Halt command. The Quit button will close the GUI, however the newAD2 will be still running in the background and you can reconnect to it by starting newAD2gui (or the command line interface newAD2) again. Several GUI and text terminals can run simultaneously.