Interference between optical transitions

Abstract

We report observations of an interference between optical transition amplitudes for linear and nonlinear excitation of the mercury 65 ] So-* 6p ] P\ transition. The transition probability is varied sinusoidally by changing the relative phase of the two fields inducing these distinct processes.

An Approach To “Quantumness” In Coherent Control

“…This control scenario is an extension of Elliott's twocolor photoionization experiments on alkali atoms [14,15,32,33], which demonstrated that the angular distribution of an emitted photoelectron can be controlled by the relative phase between two ionizing laser beams. The sensitivity to phase was attributed to quantum interference between competing ionization processes.…”

“…For example, the path alternatives are given by the two excitation processes in a 1 vs. N coherent control scenario. The resultant CCI framework is general and applicable to many systems, from atoms [15,66] to molecules [27,45,[67][68][69] to bulk solids [4,5,20,30,[70][71][72][73][74][75]. Further, the control field can be in a semiclassical coherent or in a quantum state of light, such as a multimode Fock state or a squeezed state.…”

“…In particular, they rely on the functional form of this equation, which is reminiscent of double slit interference, the phase sensitivity of the control, and the display of nonadditivity of the contributions. Early two-color photoionization experiments with alkali atoms, [14,15,32,33], serve as seminal examples of this scenario, as do experiments on current directionality in quantum wells [5] and semiconductors [20]. However, phase sensitivity and nonadditivity can also be of classical origin arising, for example, in transport processes [34].…”

Adaptive Femtosecond Quantum Control

“…It was first experimentally realized in 1989 on atoms and later also in small to medium-sized molecules [11][12][13][14]. In the model system depicted in Fig.…”

“…This spectral shift is often subtracted from the phase φ (t): 11) introducing the time dependent phase ϕ(t). With this relation, the momentary frequency ω(t), which is defined as the time-derivative of the temporal phase φ (t) can be written as:…”