Emission from a resonantly excited quantum emitter is a fascinating research topic within quantum optics and a useful source for different types of quantum light fields. The resonance spectrum consists of a single spectral line which develops into a triplet above saturation of the quantum emitter. The three closely-spaced photon channels from the resonance fluorescence (RF) have different photon statistical signatures. We present a detailed photon-statistics analysis of the RF emission triplet from a solid state-based artificial atom, i.e. a semiconductor quantum dot. The photon correlation measurements demonstrate both 'single' and 'cascaded' photon emission from the Mollow triplet sidebands. The bright and narrow sideband emission (5.9 million photons/second into the first lens) can be conveniently frequency-tuned by laser detuning over 15 times its linewidth (~ 1.0 GHz). These unique properties make the Mollow triplet sideband emission a valuable light source for, e.g. quantum light spectroscopy and quantum information applications.
Publication: Cascaded Single-Photon Emission from the Mollow Triplet Sidebands of a Quantum Dot
A. Ulhaq, S. Weiler, S. M. Ulrich, R. Roßbach, M. Jetter, and P. Michler 
Nature Photonics 6, 238 - 242 (2012)
Contact person: Prof. Peter Michler