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Showing papers on "Electromagnetically induced transparency published in 1994"


Journal ArticleDOI
TL;DR: In this paper, paired variables are defined as the normal modes for electromagnetically induced transparency and used these modes to study the propagation of matched pulses in an absorbing medium, which is the case in this paper.
Abstract: We define paired variables which are the normal modes for electromagnetically induced transparency and use these modes to study the propagation of matched pulses in an absorbing medium.

117 citations


Journal ArticleDOI
TL;DR: An electromagnetically induced transparency-like effect is described that allows a strong laser to control and reduce to unity the refractive index of a weak probe.
Abstract: An electromagnetically induced transparency-like effect is described that allows a strong laser to control and reduce to unity the refractive index of a weak probe. A lossless multistate system with all states far from resonance is considered.

67 citations


Journal ArticleDOI
TL;DR: It is shown that the recently predicted effect of pulse matching leads to a correlation of the high-frequency phase fluctuations of the fields, and may therefore be used to reduce the noise in short-time measurements of phase differences.
Abstract: A quantum analysis of the interaction of two propagating, quasimonochromatic fields with three-level \ensuremath{\Lambda}-type atoms is presented. It is shown that the recently predicted effect of pulse matching [S. Harris, Phys. Rev. Lett. 70, 552 (1993)]--the generation of fields with matched Fourier components--is due to the nonadiabatic response of the medium. This effect leads to a correlation of the high-frequency phase fluctuations of the fields, and may therefore be used to reduce the noise in short-time measurements of phase differences.

57 citations


Journal ArticleDOI
TL;DR: Electric-field-induced transparency and light amplification without population inversion of a weak probe beam in an intense coherent laser field system using generalized self-consistent density functional theory is shown.
Abstract: An intense coherent laser field couples two electron subbands in quantum wells. Using generalized self-consistent density functional theory, we study the nature of the Coulomb and light-induced electronic renormalization. We show electric-field-induced transparency and light amplification without population inversion of a weak probe beam in such a system. The effects of the pump field strength, electron density, and δ-doping position are investigated.

29 citations



Journal ArticleDOI
TL;DR: It is shown that the effect is fairly general as long as only one continuum is involved, and the efficiency for third-harmonic generation in this system with that in an intermediate two-photon resonance system is compared.
Abstract: We analyze an electromagnetically induced transparency near an autoionizing state, which is at the same time stabilized against ionization. We show that the effect is fairly general as long as only one continuum is involved. We compare the efficiency for third-harmonic generation in this system with that in an intermediate two-photon resonance system, and discuss the advantages of the former. Explicit calculations are presented for a specific autoionizing resonance in Ca.

13 citations


Journal ArticleDOI
TL;DR: In this paper, the authors consider the propagation of matched pulses in a ε-Lambda-like system, where the upper level is replaced by a continuum, and discuss how transparency and population trapping effects are affected when a realistic continuum is involved.
Abstract: We discuss how transparency and population trapping effects are affected when a realistic continuum is involved. We consider the propagation of matched pulses in a \ensuremath{\Lambda}-like system, where the upper level is replaced by a continuum.

12 citations


Journal ArticleDOI
TL;DR: In this article, the authors consider optical pumping in the multilevel sodium D1 manifold by several coherent light fields and show that the interaction of a strong and a weak field creates electromagnetically induced transparency.
Abstract: For pt. I see ibid. p. 231, 1994. We consider optical pumping in the multilevel sodium D1 manifold by several coherent light fields. Coherence between atomic states is taken into account by solving the complete density matrix equations. The manifestation of population trapping and the variation of transmitted light intensity are predicted numerically and verified experimentally for the sodium D1 line. The influence of relaxation and Doppler broadening is elucidated. The interaction of a strong and a weak field is shown to create electromagnetically induced transparency.

11 citations


Journal ArticleDOI
TL;DR: In this paper, the density matrix evolution for a three-level cascade atom is generalised to high vapour densities by the inclusion of the local field effect, and thereby, nonlinear cross-coupling terms arise.

9 citations


Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate that the application of intense laser radiation to strongly couple the 2s and 3p levels causes transparency in the 3p from 1s transition, leading to reduced absorption of the generated Lyman- beta radiation, and to increased conversion efficiency.
Abstract: Four-wave mixing in atomic hydrogen with the generation of coherent Lyman- beta radiation at 102.6 nm was investigated experimentally and theoretically in the low density limit. We demonstrate that in this doubly-resonant system, the application of intense laser radiation to strongly couple the 2s and 3p levels causes transparency in the 3p from 1s transition, leading to reduced absorption of the generated Lyman- beta radiation, and to increased conversion efficiency.

8 citations


Journal ArticleDOI
TL;DR: With a coherent pump laser coupling two electron levels in quantum wells, Coulomb and light-induced electronic renormalization is investigated according to the density-functional theory in this paper, where the optical response function for intersubband absorption of a probe light beam is studied.
Abstract: With a coherent pump laser coupling two electron levels in quantum wells, Coulomb and light-induced electronic renormalization is investigated according to the density-functional theory. On the basis of the renormalization, the optical response function for intersubband absorption of a probe light beam is studied. Both the electromagnetically induced transparency and the probe light amplification without inversion are observed. The influences of the pump field strength, frequency detuning, electron density, and δ-doping position are determined.

Journal ArticleDOI
TL;DR: In this article, the absorption and dispersion spectra of a weak probe in a closed two-level atomic system driven by a strong field were studied and the authors derived compact expressions for the inhomogeneously-broadened spectra involving Lorentzian and Gaussian broadenings, respectively.


Journal ArticleDOI
TL;DR: In this article, the Coulomb and light induced electronic renormalizations on electron and hole eigenenergies and eigenstates were studied by employing a generalized density functional approach.
Abstract: In the presence of a coherent coupling between two electron conduction sub-bands within doped quantum wells, both the Coulomb and light induced electronic renormalizations on electron and hole eigenenergies and eigenstates are studied by employing a generalized density functional approach. The dynamic properties of interband absorption of a probing laser are investigated. Electromagnetically induced transparency in interband transitions and optical switching is shown. The effects on the absorption coefficient due to pump field amplitude, electron area density, inhomogeneous level broadening, and delta -doping layer position are investigated and explained.

Journal ArticleDOI
TL;DR: Two schemes for the efficient conversion of coherent input light into bright-squeezed output light are investigated, interacting with three-level ladder-configuration atoms inside optical cavities, resulting in noise suppression for quite different tuning regimes.
Abstract: We investigate two schemes for the efficient conversion of coherent input light into bright-squeezed output light. Both schemes utilize strong signal and weak probe fields, interacting with three-level ladder-configuration atoms inside optical cavities. The schemes differ in the resonance requirements of the cavities and produce noise suppression for quite different tuning regimes. Quantum-noise reduction is a consequence of the dressing of the atoms with two coherent fields. By tuning the probe light in the right fashion, spontaneous emission from the excited state can be made to counteract signal-light intensity fluctuations.

Proceedings ArticleDOI
29 Aug 1994
Abstract: The atomic potential was chosen as a rectangular potential well of height V, = 6 eV and width d = 4 A. In such a well there exists two bound states, and the ionization potential is I = 4.8 eV. The laser quantum energy changed from 0.12 to 1.17 eV, which corresponds to the frequency band from CO, to Nd lasers. The laser pulse was assumed to have a Gaussian form with duration T = 150 fs. The maximum intensity was Po = 3 10'* 10" W/cm2. Figure 1 shows the ionization probability dependence on intensity Po for different frequencies (1 hw = 0.12 eV, 2 hw = 0.24 eV, 3 hw = 1.17 eV) obtained numerically. The value Ig(W) in cases 1 and 2 for Po 5 lo" W/cm2 is a linear function of Pi''', that is in agreement with the expression (1). For Po 2 10" W/cm2 saturation occurs and the ionization probability approaches 1. The perturbation theory, used in Ref. 1 in this case is invalid. As it follows from the theory of tunnel ionization," the ionization probability does not depend on radiation frequency. The theoretical dependency obtained by integrating of (1) over the time of laser action is shown in Fig. 1. (dashed line) and well coincides with curves 1 and 2. Another picture takes place for Nd laser radiation (hw = 1.17 eV). In this case Keldyshs parameter y > 1 and transitions to continuum occur as the result of multiquantum photoeffect. The transition from tunnel ionization regime to multiquanta photoeffect is displayed in Fig. 1 as a dependence of the ionization probability on laser frequency. 1. L. V. Keldysh, Sov. Phys. JETP, 20, 1307 (1965). 2. N. B. 'Delone, V. P. Kraynov, Atoms in Strong Light Fields. (Berlin Springer, 1985).

Proceedings ArticleDOI
31 Oct 1994
TL;DR: In this article, coherent optical effects in a quantum well system with two electron subbands coupled by a pump laser were investigated with generalized density-functional theory, and the absorption coefficient of a probe light beam was studied for intersubband transition by using a self-consistent field theory.
Abstract: Summary form only given. In this paper, we present coherent optical effects in a quantum well system with two electron subbands coupled by a pump laser. The Coulomb and light induced electronic renormalization is investigated with generalized density-functional theory. On the basis of the renormalized electron states, the absorption coefficient of a probe light beam is studied for intersubband transition by using a self-consistent field theory. Both the electromagnetically induced transparency (EMIT) and probe light amplification without population inversion are found.