OPTICAL SPECTROSCOPY OF BRAGG CONFINED TRANSITIONS IN A SUPERLATTICE WITH MULTIQUANTUM BARRIERS

Photoreflectance measurements of a doubly periodic AlGaAs/GaAs superla ttice, i.e., a multiquantum well structure with superlattice barriers, are reported. The Bragg confined transitions above the AlGaAs barrier height are observed at temperatures of 13 to 200K. The measured trans ition energies are compared to the values calculated with the envelope function approximation. Furthermore, the minigaps in the energy band structure can be resolved from the photoreflectance spectrum.