ACOUSTICALLY DRIVEN STORAGE OF LIGHT IN A QUANTUM-WELL

The strong piezoelectric fields accompanying a surface acoustic wave o n a semiconductor quantum well structure are employed to dissociate-op tically generated excitons and efficiently trap the created electron h ole pairs in the moving lateral potential superlattice of the sound wa ve. The resulting spatial separation of the photogenerated ambipolar c harges leads to an increase of the radiative lifetime by orders of mag nitude as compared to the unperturbed excitons. External and deliberat e screening of the lateral piezoelectric fields triggers radiative rec ombination after very long storage times at a remote location on the s ample.