AlGaAs/InGaAs/GaAs optoelectronic structures on (111)B GaAs

Abstract

Epitaxial growth and the crystal-orientation specific optical properties of InGaAs quantum wells and AlGaAs surface-emitting harmonic generation wave-guides on (111) substrates are discussed. The samples were grown by molecular beam epitaxy on misoriented (111)B GaAs substrates. Low As4 overpressure and a very high substrate temperature lead to excellent surface morphology for both types of structures, making their growth compatible for later monolithic integration. InGaAs quantum wells are shown to be strongly affected by the strained-induced electric field. We observe an important increase, with In content, of the resultant redshift between (111) and (100) layers; a luminescence redshift as large as 55 meV for an 18% In well is measured. We also demonstrate for the first time surface emission harmonic generation from an all-AlGaAs second harmonic generation wave-guide pumped with 1.06 μm transverse electric (TE) polarized light; as predicted theoretically, the emitted light is uniform along the guide, and as intense as on a (100) crystal for TE–TM (transverse magnetic) interaction.