Current
research effort focuses on the study of electrical spin injection in spintronic
devices. A variety of optical techniques in the visible and near-infrared
are used: reflectivity, absorption, photoluminescence and electroluminescence
spectroscopies. The experiments are carried out at liquid helium temperatures
in magnetic fields up to 8 Tesla. The spin injection efficiency is determined
from the optical spectra and the various spin-flip mechanisms are investigated.
