Optical gain in non-abrupt GaAs/AlxGa1−x quantum well lasers

The optical gain of unstrained non-abrupt GaAs/AlxGa1−xAs single quantum wells as a function of the energy of the radiation, width of the well, and interface thickness is calculated. Both the transversal electrical and the transversal magnetic light polarization are considered. All sub-bands transitions in the quantum well are taken into account. It is shown that the existence of non-abrupt interfaces decreases the gain and shifts its spectra to higher frequencies.