  The effects of random distribution of magnetic impurities with concentration
$x$ in a semiconductor alloy multilayer at a paramagnetic temperature are
investigated by means of coherent potential approximation and tight-binding
model. The change in the electronic states and the optical absorption spectrum
with $x$ is calculated for weak and strong exchange interactions between
carrier spins and localized spin moments on magnetic ions. We find that the
density of states and optical absorption are strongly layer-dependent due to
the quantum size effects. The electronic and optical spectra are broadened due
to the spin fluctuations of magnetic ions and in the case of strong exchange
interaction, an energy gap appears in both spectra. Furthermore, the interior
layers show higher contribution in the optical absorption of the system. The
results can be helpful for magneto-optical devices at a paramagnetic
temperature.
