### Quantum Well Interband Absorption

In the following tutorial we demonstrate how the interband absorption spectra can be calculated with the XienceSim software.

We used as a test structure a $GaAs$ QW in $Al_{0.3}Ga_{0.7}As$ barriers in room temperature. The with of the well was chosen to be 5nm. In order to calculate the wavefunctions with the absorption coefficients we need to select the envelope function calculator tool, and choose the single bands (HH, LH, cG) to calculate them. The simulated band structure with the single band wavefunctions from the conduction band, and heavy-hole, and light-hole states can be seen on Figure 1.

The calculated interband absorption spectra for the Quantum Well is plotted in Figure 2.

As can be seen curvature of the absorption is different in the growth direction, and in the perpendicular directions. It is due the fact that the heavy-hole electron transition is forbidden in the growth direction.