OACs of the exciton transition from E₁ to E₃ with variation of incident photon wavelength λ as a function of L_b for Zn_{1 − xl}Mg_xlO/ZnO/Zn_{1 − xc}Mg_xcO/ZnO/Zn_{1 − xr}Mg_xrO ADQWs with L_b1 = 7 nm, L_b2 = 7 nm, xl = 0.6, xc = 0.4, and xr = 0.4 for (a) L_w1 = 4 nm and L_w2 = 4 nm; (b) L_w1 = 5 nm and L_w2 = 3 nm. The right images are for ADQW1, the left ones for ADQW2.