Spatially modulated photoluminescence properties in dynamically strained GaAs/AlAs quantum wells by surface acoustic wave

Spatially resolved photoluminescence (PL) spectra and polarization anisotropy were investigated in GaAs/AlAs dynamic wires, which were formed by applying a surface acoustic wave (SAW) on GaAs/AlAs quantum wells along the [110] or [1-10] direction. A synchronized excitation method clearly demonstrates that the band gap energies are spatially modulated by the travelling-SAW-induced strain. It is found that both the spatial PL modulation and anisotropic polarization properties depend on the SAW direction. The spatial modulation of the polarization anisotropies and their dependence on the strain-induced valence band mixing are also discussed theoretically. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3703309]