Greentree, AndrewWei, ChangjiangHolmstrom, SMartin, JManson, Neil2015-12-132015-12-131464-4266http://hdl.handle.net/1885/93418A two-level system is driven by two strong fields, one on resonance and one close to resonance. There is a resonance-like response of the coupled atom-field system when the detuning of the second field is an integer fraction of the Rabi frequency of the resonant field. These subharmonic resonances are monitored by a transition to a third level and give a characteristic spectrum dominated by a series of doublets.Keywords: Photons; Resonance; Spectrum analysis; Autler-Townes effect; Multiphoton resonances; Rabi frequency; Subharmonic resonances; Quantum optics199910.1088/1464-4266/1/2/0072015-12-12