The observation of quantum-confined optical transitions in multiple-delta-doping in GaAs, grown by molecular beam epitaxy, is reported. Doping efficiency and carrier confinement are investigated by Hall and photoluminescence measurements. Hall measurement results for multiple-delta-doped samples show a dramatic enhancement of carrier concentrations compared to the uniform doping case. From photoluminescence spectra we observed that the cutoff energy is significantly affected by the spacing between the dopant sheets. The strong localization of confined photoexcited holes in the spacing layers of these structures plays a fundamental role in the interpretation of the optical data.602328952896