Optically controlled excitonic absorption in GaAs/AlGaAs quantum wells: roles of confinement and interchannel coupling

We calculate optically controlled excitonic absorption in GaAs/Al0.3Ga0.7As wells using a multichannel Liouville--Fourier response with outgoing boundaries. At 77 K,10 kV/cm, and an optical HWHM of 0.5 meV, widening the well from 10 to 12 nm after resonance-detuning compensation increases the dip depth from 82.9% to 86.0% and its half-contrast width from 1.60 to 1.89 meV. Removing Coulomb coupling between the electron--heavy-hole channels e2hh1 and e1hh2, or the hole control dipole, changes the reference spectrum by up to 10.2% and 2.6% of its full-model maximum within the comparison window. Restoring resonance therefore does not restore absorption suppression across different well widths.