Probe absorption, quantum interference

The narrow resonances produced by quantum interference may also be observed in the absorption spectrum of a three-level atom probed by a weak field of the frequency o> ). Zhou and Swain [10] have calculated the absorption spectrum of a probe field monitoring E-type three-level atoms with degenerate (A = 0) as well as nondegenerate (A / 0) transitions and have demonstrated that quantum... 

Zhou and Swain [10] have shown that in the presence of initial correlations between the upper states, the hole in the center of the spectrum can reach negative values, indicating that the probe can be amplified as a result of quantum interference. Paspalakis and Knight [39] have calculated the absorption... 

Figure 13, together with the transition dipole moments and transition rates, provides a simple interpretation of the absorption rate shown in Fig. 11. According to Eq. (139), the emissive peak in the absorption rate appears on an almost completely inverted transition ( a,iV) — —, N — 1)), whose dipole moment is significantly reduced by quantum interference. One could expect that the weaker field should not couple to an almost canceled dipole moment. However, we have assumed that the probe field couples only to the dipole moment p12. From Eq. (136), we find that the coupling strength of the probe field to the transition a. (V) —. /V 1) is proportional to j (Sp12 despite the...

Rabi frequeney of the eoupling laser and result in two transition paths ( l> +> and 1>—> ->) for the probe laser (Fig. 1(b)). On the resonance frequency of the bare state transition 1> —> 3>, the quantum interferenee between the two transition paths is destructive due to the opposite frequency detuning and leads to the suppression of the probe light absorption, rendering the three-level atomic medium transparent to the probe laser. Since the two transitions are linear and are connected by the same probe laser field, the quantum interference is independent of the probe laser phase and is destructive only. 

---