INTRINSIC AND EXTRINSIC PROCESSES IN PHOTOLUMINESCENCE, REFLECTIVITY,AND SPIN DYNAMICS OF GAAS QUANTUM-WELLS

The intrinsic optical properties of two-dimensional excitons in quantu m wells include rapid radiative recombination, fast electron-spin rela xation, and high-reflectivity modulation. The sample-to-sample variati ons in the observed properties are shown to be due to phonon, defect, and impurity scattering processes. We identify the various components of the photoluminescence and reflectivity line shapes through extensiv e optical measurements on a series of GaAs quantum-well samples. We pr esent experimental evidence that demonstrates that the optical reflect ivity and the time-resolved-polarized luminescence data may be used as very sensitive probes of the intrinsic and the extrinsic processes. ( C) 1996 Optical Society of America.