Investigation on the polarized bound-to-continuum intersub-band transitions in the mid-infrared region for InAs quantum dots

In this paper, the electronic of a truncated pyramid shaped InAs/GaAs quantum dots are theoretically investigated and the mid/far infrared spectral are calculated for a variety of structures and polarizations. In order to predict the optical properties of this model, transition dipole moment for three main bound-to-bound and bound-to-continuum transitions were studied as a function of incident light polarization and dot structure. The in-plane polarized transitions of the bound-to-bound (S-to-P) and bound-to-continuum (P-to-Wetting layer), which both are in-plane polarized transitions, are independent of quantum dots height. However, they indicate a competition behavior for the WL thickness and the dot base length impacts on the transition dipole moment trends. This simulation predicts that the flatness of the InAs/GaAs dots presented by larger base length dominates the other lateral parameter, wetting layer thickness. The z-polarized bound-to-continuum (S-to-Wetting layer) transition is noticeable for tall dots where it is found to be consistent with experimentally measured intersub-band transitions with transverse-magnetic light injection for the schemed quantum dot infrared photodetectors.