All-Optical Tuning of Indistinguishable Single Photons Generated in Three-Level Quantum Systems

Resonance fluorescence of two-level quantum systems has emerged as a powerful tool in quantum informationprocessing. Extension of this approach to higher-level systemsprovides new opportunities for quantum optics applications. Herewe introduce an all-optical tuning functionality into a well-established resonancefluorescence coherent driving scheme. Weaccomplish this by resonant excitation of a three-level laddersystem with two laserfields utilizing Autler-Townes and ac Starkeffects. We propose theoretically and demonstrate experimentallythe feasibility of this approach toward all-optical spectral tuning ofquantum-dot-based single-photon sources and investigate photonindistinguishability and purity levels. Our tuning technique allowsfor fast optical control of the quantum emitter spectrum whichpaves the way toward temporal and spectral shaping of the single photons, formation of topological Floquet states, or generation ofhigh-dimensional frequency-encoded quantum states of light