  We report on the detection of the intrinsic spin Hall effect in a modulation
doped Al-GaAs/GaAs/AlGaAs heterostructure bounded by a self-aligned
pn-junction, fabricated by the cleaved edge overgrowth method. Light emission
due to the recombination of electrons and spin-polarized holes was generated
and mapped with a spatial resolution of one micrometer. An edge accumulated
spin polarization of up to 11% was measured, induced solely by application of
an electric Field perpendicular to the pn-junction. Using a quantum dot
structure as light source, a linear dependence of the effective spin
polarization, and with that the dominance of the spin Hall effect, with the
electric field is seen. Spatially resolved spectroscopy from an epitaxially
fabricated LED is demonstrated to be a valuable tool to probe the edge states
of electron and hole gases in reduced dimensions.
