Combining fast electrical control and resonant excitation to create a wavelength-tunable and coherent quantum-dot light source

摘要

We have realized an ultrafast diode containing a single quantum dot, whose transitions can be Stark shifted in a few hundred picoseconds. Carrying out resonant excitation of this sample we demonstrate pulsed single photon emission with high spectral purity, by rapidly sweeping the neutral exciton transition into and out of the laser energy. Detailed study of the detuning dependence of the fluorescence reveals sources of decoherence in this sample, which we show can be filtered out with narrow-band excitation.