Abstract

We report the first measurements of excitonic absorption in undoped GaAs single quantum wells for light propagating along the plane of the layers. We also observed for the first time nonlinear absorption for a field polarized normal to the layers. The samples consisted of leaky waveguide structures in which a single GaAs quantum well is embedded in a GaAs/AlGaAs superlattice grown on a GaAs substrate. The quantum wells exhibit two series of excitons formed from the electrons and the predominantly heavy holes (hh) or the predominantly light holes (lh), respectively. When the incident polarization was parallel to the layers (solid curve in Fig. 1) we observed both hh and lh excitons in agreement with previous measurements.¹ We have also observed for the first time linear and nonlinear absorption for the perpendicular polarization (dashed curve in Fig. 1).

© 1985 Optical Society of America