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 the reflectance of a semi-infinite silicon substrate.

Prepare a new directory including a 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 constant definitions for this model (the dispersion model calculates the dielectric tensor) and the modeled functions section contains the 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)
```
Download modelfile
Start newAD2gui and select the directory with the prepared modelfile.
Click on Model -> Load from File and select your modelfile. If problems occur during modelfile loading, a red error message will be shown in the bottom tray. In that case, clicking the Messages button will show more details.
Click Calculate to start the calculation.
After the calculation finishes, use grapherAD2 (Run Grapher button) to display the calculated optical constants.
Besides optical constants, newAD2 can also be used to model other optical quantities. As an example we will model the reflectance of a semi-infinite silicon substrate. The modelfile from the first part will be used as a starting point; however, some extension is needed. A new model for the ambient is needed in the media section (model Vacuum). A new boundary system definition (complex Yeh boundary matrix M for the vacuum/cSi interface) is also needed, as well as a measurement style (Surface, which corresponds to the Mueller matrix of light reflected from a semi-infinite medium, R). The corresponding function for reflectance measurements is M00, i.e. the \(M_{00}\) component of the Mueller matrix. The final modelfile can look like this: Download modelfile
In the example, the temperature dependence of the quantities is demonstrated. Use the grapher to check the results. If you want to export data, use the Output button. It will output all calculated quantities into a text file.
After the calculation finishes, the program can be completely stopped using the Halt command. The Quit button will close the GUI; however, newAD2 will still be 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.