Interface profiles and in-plane anisotropy in common anion type-$\mathrm{I}$ ${\mathrm{Cd}}_{1-x}{\mathrm{Mg}}_x\mathrm{Te}/\mathrm{CdTe}/{\mathrm{Cd}}_{1-x}{\mathrm{Mn}}_x\mathrm{Te}$ heterostructures studied by reflectivity

We report on the experimental study of the in-plane optical anisotropy of CdTe-based quantum wells with asymmetric barriers made of (Cd,Mg)Te or (Cd,Mn)Te ternary compounds. We observe a significant linear polarization of the fundamental excitonic transitions along the $〈110〉$ directions. The measured polarization rates are analyzed in the framework of an envelope function theory incorporating interface symmetry reduction for intermixed composition profiles. Fitting the experimental data produces interface anisotropy parameters that are larger than the ones predicted by a recent microscopic theory. The analysis shows an important influence of the interface profile asymmetry on the observed in-plane anisotropy.