We investigated the three-photon spectrum of quantum dot resonance fluorescence, revealing significantly more pronounced photon antibunching at the Mollow triplet sidebands and more strongly correlated emission through virtual states than at second order.
Recently, the concept of an ''N-photon spectrum'' -- a spectrally resolved N-photon correlation function -- has been introduced as an innovative quantum optics characterization tool that uniquely reveals information about pathways underlying the generation of light in a given source. Here, the authors investigate experimentally the three-photon spectrum of resonance fluorescence from a single semiconductor quantum dot. The observations agree with previous theoretical work, revealing significantly more pronounced photon antibunching at the Mollow triplet sidebands and more strongly correlated emission through virtual states compared to the two-photon counterpart.
We investigated third-order correlations between photons from a single quantum dot's resonance fluorescence in the strong excitation regime originating from opposite sidebands of the power spectrum. The three-time correlation measurements for photons filtered using three independent Fabry-Perot etalons resulted in correlation maps with ``antibunching'' features as a consequence of correlations originating from the same sideband, and ``bunching ridges'' due to opposite sideband correlated photons.
We show that the resonance fluorescence spectrum of a quantum dot excited by a strong optical pulse contains multiple peaks beyond those of the Mollow triplet. We show that as the area of the optical pulse is increased, new side peaks split off the central peak and shift in frequency. A simple analytical theory has been derived, which quantitatively accounts for the appearance and position of the peaks. This theory explains the physics responsible for the multiple peaks. By considering the time-dependent spectrum we demonstrate a time ordering of the side peaks, which is further evidence for the suggested physical explanation.