Systematic study of Mn-doping trends in optical properties of (Ga,Mn)As.

We report on a systematic study of optical properties of (Ga,Mn)As epilayers spanning the wide range of accessible Mn(Ga) dopings. The material synthesis was optimized for each nominal Mn doping in order to obtain films which are as close as possible to uniform uncompensated (Ga,Mn)As mixed crystals. We observe a broad maximum in the mid-infrared absorption spectra whose position exhibits a prevailing blueshift for increasing Mn doping.