Abstract
We report a new mechanism of photoluminescence up-conversion in undoped GaAs-AlGaAs asymmetric coupled quantum wells. Under band-to-band excitation, resonant excitation of the → intersubband transition is shown to result in a finite nonthermal occupation of the subband, giving rise to an → photoluminescence. The induced luminescence closely follows the polarization selection rules and the spectral dependence of the intersubband absorption. We show that this up-conversion scheme can be used to estimate the intersubband scattering time, which is found to be 2.5±0.7 ps.
- Received 20 October 1992
DOI:https://doi.org/10.1103/PhysRevLett.70.1018
©1993 American Physical Society