PHOTOREFLECTANCE MEASUREMENTS IN GAAS ALGAAS ASYMMETRIC QUANTUM-WELLS/

In this work we investigated the optical control of the bidimensional electron gas density in a single asymmetric quantum well using, for th e first time, photoreflectance. We performed our measurements at 80 an d 300 K as a function of the power density of the pump beam. Under str ong illumination, the bidimensional electron gas density is washed out of the quantum well and under a dark condition, it reaches its maximu m value. The variation of the optical transitions observed in our phot oreflectance spectra was related to the induced changes of the band pr ofile in between these two limiting cases. (C) 1997 Academic Press Lim ited.