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Journal ArticleDOI

Splitting of electromagnetically induced transparency under strong-probe conditions due to Doppler averaging

28 Sep 2008-Journal of Physics B (Institute of Physics)-Vol. 41, Iss: 18, pp 185504
TL;DR: In this article, the authors studied the phenomenon of electromagnetically induced transparency (EIT) in room-temperature Rb vapour under conditions of a strong probe laser.
Abstract: We study the phenomenon of electromagnetically induced transparency (EIT) in room-temperature Rb vapour under conditions of a strong probe laser. The atoms form a ladder system with the lower transition coupled by the probe laser and the upper transition coupled by the control laser. Density-matrix analysis of the system shows that, for zero-velocity atoms, the strong probe beam causes a reduction in absorption and broadening of the profile. But the lineshape after thermal averaging shows a splitting of the EIT resonance and enhanced absorption near line centre. The experimental observations in $^{85}Rb$ agree qualitatively with the predicted lineshapes.
Citations
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Journal ArticleDOI
TL;DR: In this article, a high-accuracy wavelength meter for tunable laser using a scanning Michelson interferometer and a reference laser of known wavelength was built using a frequency-stabilized diode laser.
Abstract: We have built a high-accuracy wavelength meter for tunable lasers using a scanning Michelson interferometer and a reference laser of known wavelength. The reference laser is a frequency stabilized diode laser locked to an atomic transition in Rb. The wavemeter has a statistical error per measurement of 5 parts in $10^7$ which can be reduced considerably by averaging. Using a second stabilized diode laser, we have verified that systematic errors are below 4 parts in $10^8$.

36 citations

Journal ArticleDOI
TL;DR: In this article, the rotation of the plane of polarization of a laser beam passing through room-temperature Rb vapour was studied. Butler et al. showed that the rotation occurs because the medium behaves differently for the two orthogonallypolarized components, displaying what is known as circular birefringence or linear dichroism.
Abstract: We experimentally study the rotation of the plane of polarization of a laser beam passing through room-temperature Rb vapour. The rotation occurs because the medium behaves differently for the two orthogonally-polarized components, displaying what is known as circular birefringence or linear dichroism. The difference is induced either by a control laser applied to an auxiliary transition of a ladder-type system, or by an applied axial magnetic field. In the presence of both control laser and magnetic field, the line shape shows an interesting interplay between the two effects with regions of suppressed and enhanced rotation. The line shapes can be understood qualitatively based on a density-matrix analysis of the system.

33 citations


Cites background from "Splitting of electromagnetically in..."

  • ...Indeed, EIT experiments on this ladder system show a single transparency dip from the resonant F = 4 level, and no additional dip due to the off-resonant F = 3 level [27]....

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Journal ArticleDOI
TL;DR: In this paper, a theoretical model using the density matrix approach has been presented to show the influence of multiple excited states on electromagnetically induced transparency (EIT) in a cascade-type Doppler broadened medium.
Abstract: A theoretical model using the density matrix approach has been presented to show the influence of multiple excited states on electromagnetically induced transparency (EIT) in a cascade-type Doppler broadened medium. A five-level system has been considered that is a simple case of the 87Rb atom. In a room temperature vapour, when the Doppler broadening is comparable with hyperfine splitting in the middle states, there is a strong reduction in EIT. By performing the thermal averaging in the five-level Doppler broadened system, we observe an asymmetric transparency that has already been shown in most of the experimental work.

28 citations

Journal ArticleDOI
TL;DR: In this paper, a diagrammatic method for complete characterization of multiphoton processes in three-level atomic systems is presented, where the interaction routes of the coupling and probe photons for a ladder-type, threelevel, non-cycling (or cycling) atomic system are considered.
Abstract: We present a diagrammatic method for complete characterization of multiphoton processes in three-level atomic systems. By considering the interaction routes of the coupling and probe photons for a ladder-type, three-level, noncycling (or cycling) atomic system, we are able to completely discriminate between the pure one-photon and the pure two-photon resonance effects, and the effect of their combination in electromagnetically induced transparency (EIT) using our diagrammatic method. We show that the proposed diagrammatic method is very useful for the analysis of multiphoton processes in ladder-type EIT.

24 citations

Journal ArticleDOI
TL;DR: In this article, Chanu et al. presented a detailed theoretical study of the different possible subsystems created by the doubly driven ε-Lambda system and explored the possibility of tuning the strength of individual subsystems by changing the polarization of the control lasers.
Abstract: The well-known $\ensuremath{\Lambda}$ system using two ground-state hyperfine levels, ${F}_{g}=1$ and ${F}_{g}=2$ of $5{S}_{1/2}$, and one hyperfine level, ${F}_{e}=2$ of excited state of $5{P}_{3/2}$ of ${}^{87}$Rb, has been recently studied using two counterpropagating control lasers [Sapam Ranjita Chanu, Kanhaiya Pandey, and Vasant Natarajan, Europhys. Lett. 98, 44009 (2012)]. The experiment shows conversion of electromagnetically induced transparency into electromagnetically induced absorption because the doubly driven $\ensuremath{\Lambda}$ system forms various subsystems. We here present a detailed theoretical study of the different possible subsystems created by this configuration. We also explore the possibility of tuning the strength of individual subsystems by changing the polarization of the control lasers.

22 citations


Additional excerpts

  • ...[31] Kanhaiya Pandey and Vasant Natarajan....

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References
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Journal ArticleDOI
18 Feb 1999-Nature
TL;DR: In this paper, an experimental demonstration of electromagnetically induced transparency in an ultracold gas of sodium atoms, in which the optical pulses propagate at twenty million times slower than the speed of light in a vacuum, is presented.
Abstract: Techniques that use quantum interference effects are being actively investigated to manipulate the optical properties of quantum systems1. One such example is electromagnetically induced transparency, a quantum effect that permits the propagation of light pulses through an otherwise opaque medium2,3,4,5. Here we report an experimental demonstration of electromagnetically induced transparency in an ultracold gas of sodium atoms, in which the optical pulses propagate at twenty million times slower than the speed of light in a vacuum. The gas is cooled to nanokelvin temperatures by laser and evaporative cooling6,7,8,9,10. The quantum interference controlling the optical properties of the medium is set up by a ‘coupling’ laser beam propagating at a right angle to the pulsed ‘probe’ beam. At nanokelvin temperatures, the variation of refractive index with probe frequency can be made very steep. In conjunction with the high atomic density, this results in the exceptionally low light speeds observed. By cooling the cloud below the transition temperature for Bose–Einstein condensation11,12,13 (causing a macroscopic population of alkali atoms in the quantum ground state of the confining potential), we observe even lower pulse propagation velocities (17?m?s−1) owing to the increased atom density. We report an inferred nonlinear refractive index of 0.18?cm2?W−1 and find that the system shows exceptionally large optical nonlinearities, which are of potential fundamental and technological interest for quantum optics.

3,438 citations

Journal ArticleDOI
TL;DR: Electromagnetic induced transparency is a technique for eliminating the effect of a medium on a propagating beam of electromagnetic radiation EIT may also be used, but under more limited conditions, to eliminate optical self-focusing and defocusing and to improve the transmission of laser beams through inhomogeneous refracting gases and metal vapors, as figure 1 illustrates.
Abstract: Electromagnetically induced transparency is a technique for eliminating the effect of a medium on a propagating beam of electromagnetic radiation EIT may also be used, but under more limited conditions, to eliminate optical self‐focusing and defocusing and to improve the transmission of laser beams through inhomogeneous refracting gases and metal vapors, as figure 1 illustrates The technique may be used to create large populations of coherently driven uniformly phased atoms, thereby making possible new types of optoelectronic devices

3,269 citations

Journal ArticleDOI
TL;DR: In this paper, the authors report the first demonstration of a technique by which an optically thick medium may be rendered transparent by applying a temporally smooth coupling laser between a bound state of an atom and the upper state of the transition which is to be made transparent.
Abstract: We report the first demonstration of a technique by which an optically thick medium may be rendered transparent. The transparency results from a destructive interference of two dressed states which are created by applying a temporally smooth coupling laser between a bound state of an atom and the upper state of the transition which is to be made transparent. The transmittance of an autoionizing (ultraviolet) transition in Sr is changed from exp(-20) without a coupling laser present to exp(-1) in the presence of a coupling laser.

2,325 citations

Proceedings Article
12 May 1991
TL;DR: The first demonstration of a technique by which an optically thick medium may be rendered transparent is reported, which results from a destructive interference of two dressed states created by applying a temporally smooth coupling laser between a bound state of an atom and the upper state of the transition which is to be made transparent.
Abstract: We report the results of an experiment showing how an opaque atomic transition in neutral Strontium may be rendered transparent to radiation at its resonance frequency. This is accomplished by applying an electromagnetic coupling field (Fig. 1) between the upper state 4d5d1D2 of the transition and another state 4d5p1D2; of the atom. When the Rabi frequency of the coupling field exceeds the inhomogeneous width of the 5s5p1P1–4d5d1D2; transition, the medium becomes transparent on line center.

1,999 citations

Journal ArticleDOI
TL;DR: In this paper, a strong coupling field between a metastable state and the upper state of an allowed transition to ground was proposed to obtain a resonantly enhanced third-order susceptibility while at the same time inducing transparency of the media.
Abstract: We show that by applying a strong-coupling field between a metastable state and the upper state of an allowed transition to ground one may obtain a resonantly enhanced third-order susceptibility while at the same time inducing transparency of the media. An improvement in conversion efficiency and parametric gain, as compared to weak-coupling field behavior, of many orders of magnitude is predicted.

1,287 citations