Inhibition of two-photon absorption in a three-level system with a pair of bichromatic fields

Quantum Interstate Phase Differences and Multiphoton Processes: Quantum Jumps or Dynamic Beats?

“…However, if multiphoton processes can be detected experimentally in a system with short phase coherence time (whether limited by the phase coherence time of the field or by collisions that destroy the phase of system states) compared to the time for population inversion, our picture may need revision. However, experiments by Zou et al have shown the importance of phase relationships in laser fields, and calculations by Pollnau show phase relationships in emission and absorption similar to our results. In addition, experiments by Minov et al and many others , and can often be interpreted in terms of a deterministic dynamics for quantum transitions similar to those we have demonstrated here.…”

Spectral properties of a Ξ-configuration atom driven by a pair of bichromatic fields

“…−hg(a 2 e −iω 2 t+iφ 2 + a 4 e −iω 4 t+iφ 4 )σ 23 + c.c. (24) In the case of large δ , it has been demonstrated in the same model [10] that the eigenstates of the coupling system form two two-photon absorption channels. There are four states in the dressed-state picture: the mutual top and bottom states are |1 and |3 , and the intermediate states are denoted by |+ and |− which are equal to |2 and −|2 in the case of large δ .…”

“…, where x l i represents the slowly varying amplitudes, [10] then substitute the decompositions into the equations of motion for x i (τ), finally equate the coefficients of harmonics of δ and obtain the equations of motion of the slowly varying amplitudes x l i , which reads…”

“…The alteration in the fluorescence spectra for different values of Ω 1 and Ω 3 can be interpreted as: when 014205-6 the strengths of Ω 1 and Ω 3 are adjusted to a value which are unequal to the values of Ω 2 and Ω 4 , the condition under which the suppression of two-photon absorption is broken. [10] Hence the population probabilities of states |1 and |2 are increased, which results in an enhancement of the spontaneous transitions |1 → |2 and |2 → |3 . For a very strong Ω 1 and Ω 3 (Ω 1 , Ω 3 > 8), the coupling between |1 and |2 is stronger than that between |2 and |3 .…”

“…[9] Some other configurations of atomic systems driven by polychromatic fields are also discussed. [10][11][12] More recently, some researchers' works show that some new effects in the medium driven by a bichromatic field have promising importance in some optical information processes such as quantum memory, [13] bright entangled source of light, [14] bichromatic pulse propagating, [15] and some other related technologies including high-precision EIT vector magnetometer, [16] atom interferometer, [17] and attosecond pulse generation. [18] As we know, when polychromatic field driving is introduced, the system always demonstrates a variety of phasedependent behavior, such as phase-dependent absorptive profile, [19,20] coherent population trapping, [21] manipulation of Kerr nonlinearity, [22] and coherent phase control in electron scattering.…”