Two-photon effects in continuous-wave electromagnetically-induced transparency

Transmittance signal in real ladder-type atoms

“…In the case of ladder-type atomic systems in alkali-metal atoms, the two-photon atomic coherence and the optical-pumping effects cannot be distinguished from changes in the EIT spectrum; this is because the frequency of double-resonance optical pumping (DROP) occurs under the conditions of two-photon resonance in a similar manner to that of EIT [21]. A further, serious problem is that the transmittance signal due to optical pumping is often confused with EIT in many studies of ladder-type EIT in alkali-metal atoms [13][14][15][16][17][18][19][20]. The basis of this misunderstanding is that in EIT real ladder-type atoms are modeled as simple three-level atomic systems without including the DROP effect [19].…”

“…Ladder-type EIT has been demonstrated in many kinds of atoms, including sodium [13], rubidium [14][15][16][17][18][19], and cesium [20]. In the case of ladder-type atomic systems in alkali-metal atoms, the two-photon atomic coherence and the optical-pumping effects cannot be distinguished from changes in the EIT spectrum; this is because the frequency of double-resonance optical pumping (DROP) occurs under the conditions of two-photon resonance in a similar manner to that of EIT [21].…”

Diagrammatic analysis of multiphoton processes in a ladder-type three-level atomic system

“…This is because it can be applied to many valuable researches such as quantum information [5], light storage [6], and precision magnetometer [7]. EIT was investigated for many atomic species such as Rb, Na, or Cs [8][9][10][11][12][13][14] and for a variety of laser configuration [ , V, and ladder (or cascade) system] [1]. Of these configurations, ladder scheme has drawn much interest recently owing to its applications such as coherent control of polarization [15], study of Rydberg states [16], and multiwave mixing [17].…”

“…(9), we can obtain the same results as in Eq. (8). Therefore we can interpret the terms in the various orders of 1 and 2 by means of the corresponding many interaction pathways from the point 0 1 0 2…”

Interferometric control of parametrically amplified waveforms

“…E 1 induces stimulated emission in the phase-matched direction k f , resulting in the FWM signal E f1 . The waveform of this signal is governed not only by the TPR features including power broadening and Autler-Townes splitting [20,21], but also by the various closely lying hyperfine (hf) sublevels of the excited state that lie within the EIT linewidth. Since the hf levels have different multiplicities and transition strengths, their contributions to the generated signal vary in strength, inducing asymmetries in the generated waveform [ Fig.…”