Temporal response of the optically generated electric field in InAs/GaAs coupled quantum dots

Coupled quantum dots (CQDs) can provide a sensitive probe of the electric field within a device. With non-resonant excitation above the wetting layer (WL) energy, optical generation of an electric field within the CQD structure was observed. By alternating this non-resonant excitation the temporal response of the optically generated electric field was measured. Decay of this field was measured to be on the order of 110-140 μsec whereas the onset of the optically generated electric field was observed to be less than the temporal resolution of our experiment (7.5 μsec). This may provide a means for fast, non-contact, electric field modulation techniques.