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1.
Marina Movsisyan Svetlana Shmavonyan Aram Papoyan 《Central European Journal of Physics》2011,9(4):948-955
We present the results of spectroscopic and polarization studies of dilute rubidium vapor exposed to a single-frequency linearly
polarized diode laser radiation in a spectral range of atomic D2 line. We report the origin of a circularly polarized radiation on V-type transitions of 87Rb F
g
= 2 → F
e
= 3 and 85Rb F
g
= 3 → F
e
= 4, and amplification of this radiation in backward direction caused by a partial population inversion among magnetic sublevels
of the ground and excited levels. This is confirmed experimentally by high directivity of backward radiation, absence in its
spectrum of 85Rb F
g
= 2 → F
e
= 1 (Λ-type) radiation, as well as by different nature of intensity dependences of backward and fluorescence radiations. 相似文献
2.
This paper has observed linewidth narrowing of dark states in rubidium cell by using the Hanle configuration. The reduction of the coherent resonance width under the transition of ^87Rb Fg = 1 → Fe = 0 is observed and the qualitative explanation about its mechanism is presented. Multiple subnatural width dips are obtained with a linearly polarized laser beam for the transitions of ^87Rb Fg = 1→Fe = 0, 1, 2. The feature of negative and positive slope, namely dispersionlike feature, is observed in the transmitted light. 相似文献
3.
A.V. Papoyan M. Auzinsh K. Bergmann 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(1):63-71
We report results of a theoretical and experimental study of the ground state nonlinear Hanle effect under strong laser excitation.
It is shown that besides the well-known zero-magnetic field suppression of absorption on F
g = F→F
e = F - 1 transitions caused by population trapping, an optical pumping induced enhanced absorption occurs on F
g = F→F
e = F + 1 transitions for small B-fields. The latter effect becomes more pronounced for high F values. The experiment with atomic vapor of Cs (D2 line, F
g = 4) confirms an increase of the spectrally unresolved fluorescence yield at zero magnetic field and 600 mW/cm2 laser intensity by 9% or 42%, when excitation occurs with linearly or circularly polarized light, respectively. The results
of the experiment agree with numerical simulation studies using equations of motion for a density matrix.
Received 24 November 2001 / Received in final form 25 March 2002 Published online 24 September 2002 相似文献
4.
5.
We study phenomenon of electromagnetically induced absorption (EIA) in the Hanle configuration by applying a perturbative
method to solve linear system of optical Bloch equations (OBEs) for the case of closed F
g
= 1 → F
e
= 2 transition. The method is applied assuming stationary case and a weak laser fields (Ω ≪ Γ, i.e., Rabi frequency small
compared to spontaneous emission rate). This way, we calculate (both numerically and analytically) higher order corrections
to density matrix. Odd corrections give contributions to optical coherences, while even corrections contribute to populations
and Zeeman coherences. The method gives insight into mechanism of transfer of coherences and transfer of populations between
Zeeman sublevels. We have found that the ground-state coherences (2nd correction to coherences) are crucial for the 4th correction
to the change of populations which brings EIA type behavior of the Hanle spectrum. Using exact analytical expressions we further
discuss further the role of decoherence of the ground-state sublevels when forming EIA. 相似文献
6.
M. Kajita N. Kotake K. Fukuda A. Hasegawa T. Morikawa 《Applied physics. B, Lasers and optics》1997,65(4-5):563-568
g =4→Fe
′=5 transition. As the detuning becomes larger, the equilibrium temperature becomes lower. When the detuning is larger than
150 MHz, the influence of the Fg=4→Fe
′=4 transition also becomes significant. We show our numerical analysis of polarization gradient cooling, taking into account
actual sublevels of the ground state and two excited states. We conclude that it is preferable to use a detuning of greater
than 180 MHz, to get both a high deceleration and low equilibrium temperature.
Received: 25 September 1996/Revised version: 10 January 1997 相似文献
7.
We investigate theoretically the pump-probe spectroscopy of coherently-driven four-level Λ system with two closely spaced
excited common levels, thereby forming a double Λ system. Using the master equation approach, analytical results are obtained
for the absorption spectrum of a weak probe in the presence of a strong pump. The model is applied to the double Λ system
52
S
1/2
F = 1, 2 → 52
P
3/2
F′ = 1,2 of 87Rb atom. It is shown that the absorption spectrum consists of a triplet, of which one resonance is of sub-natural linewidth
depending on the atom-field interaction parameters. The effect of Doppler broadening on the absorption spectrum is also investigated. 相似文献
8.
An analytical method is developed for finding the exact stationary solution for the density matrix of atoms in a monochromatic
resonance field of arbitrary ellipticity and intensity. A solution for the transitions F
g=F → F
e=F+1 (F
g and F
e are the angular momenta of the ground and excited states) is obtained in an analytical invariant form. The properties of
this solution are investigated.
Pis'ma Zh. éksp. Teor. Fiz. 64, No. 1, 8–12 (10 July 1996) 相似文献
9.
P. L. Chapovsky 《JETP Letters》2012,95(3):132-136
A setup for preparing the Bose-Einstein condensate of rubidium atoms has been built. The condensate consists of 105–106
87Rb atoms in the hyperfine state F
g = 2 of the ground electronic state. Three key indications of condensation—a sharp increase in the phase-space density of
atoms, the threshold emergence of two fractions in the cloud, and anisotropic expansion of the condensate—have been observed. 相似文献
10.
The resonances of coherent population trapping (CPT) excited by a frequency-modulated (FM) field at the Zeeman sublevels during the transition F g = 2 → F e = 1 of the 87Rb D 1-absorption line were studied theoretically. The influence of the nonlinear Zeeman effect on the structure of the observed resonances was considered. The spectra of CPT resonances were calculated for different values of magnetic field induction and compared with the experimental data. 相似文献
11.
P. Rosenbusch 《Applied physics. B, Lasers and optics》2009,95(2):227-235
We investigate the hyperfine transition of magnetically trapped non-condensed atoms. The two principal frequency shifts, the
second order Zeeman effect and the mean field interaction are considered. Analytic models of the mean frequency and its trap
induced spread are developed. Comparisons with existing experiments evaluate the role of the atoms’ oscillatory motion. The
analytic model proves to be equivalent to existing Monte Carlo simulations. The formulae provide a simple tool for optimising
the design of a new experiment. Applied to the two-photon transition |F=1,m
F
=−1〉→|F=2,m
F
=1〉 in 87Rb and the conditions of a typical atom chip experiment, a line spread as small as 11 mHz is predicted giving a quality factor
of 1012. The system is promising for application in precision instruments such as compact atomic clocks. 相似文献
12.
V.B. Tiwari S. Singh S.R. Mishra H.S. Rawat S.C. Mehendale 《Applied physics. B, Lasers and optics》2006,83(1):93-96
We report on a Doppler-free polarization spectroscopy based technique of laser frequency stabilization using a balanced bi-polarimeter
set-up. Two linearly polarized weak laser beams are used to probe birefringence induced by two oppositely circularly polarized
strong pump beams in a vapour cell. Subtraction of balanced polarimeter signals obtained from the two probe beams results
in a background-free dispersion-like reference signal without frequency modulation. The dispersion-like signal corresponding
to the closed transition 5 2
S
1/2 (F=2) →5 2
P
3/2 (F′=3) of 87Rb was used for frequency locking of a diode laser. The frequency fluctuations and the drift were measured to be less than
0.25 MHz and 0.02 MHz, respectively, for an observation period of more than 10 hours.
PACS 42.62.Fi; 42.55.Px; 32.30.-r 相似文献
13.
A. N. Kozlov S. A. Zibrov A. A. Zibrov V. I. Yudin A. V. Taichenachev V. P. Yakovlev E. A. Tsygankov A. S. Zibrov V. V. Vassiliev V. L. Velichansky 《Journal of Experimental and Theoretical Physics》2016,122(5):823-831
Magnetic resonance at the Fg = 1 \( \rightleftarrows \)Fe = 1 transition of the D1 line in 87Rb has been studied with pumping and detection by linearly polarized radiation and detection at the double frequency of the radiofrequency field. The intervals of allowed values of the static and alternating magnetic fields in which magnetic resonance has a single maximum have been found. The structure appearing beyond these intervals has been explained. It has been shown that the quadratic Zeeman shift is responsible for the three-peak structure of resonance; the radiofrequency shift results in the appearance of additional extrema in resonance, which can be used to determine the relaxation constant Γ2. The possibility of application in magnetometry has been discussed. 相似文献
14.
The absorption of the tunable narrow-band laser radiation with λ = 276.9 nm at the 62
P
1/2 → 62
D
3/2 transition in the atomic thallium beam is experimentally studied. The isotopic selectivity and efficiency of the excitation
of the 62
D
3/2 state is investigated. The splittings between the 203Tl and 205Tl isotopes were found to be Δv = 0.98 and 1.25 GHz for the transitions with the nuclear momenta F = 1 → F = 1, 2 and F = 0 → F = 1, respectively, which is sufficient for a relatively high isotopic selectivity of the 62
D
3/2 state excitation with the subsequent ionization for the laser separation of the thallium isotopes. The effects that lead
to the broadening of the resonance and a decrease in the selectivity are analyzed. The main contribution is related to the
field broadening by the laser radiation, which limits the mean laser power density. 相似文献
15.
D. Sarkisyan T. Becker A. Papoyan P. Thoumany H. Walther 《Applied physics. B, Lasers and optics》2003,76(6):625-631
An extremely thin cell (ETC) with the thickness of a Rb atomic vapor layer in the range of 100–300 nm was fabricated. It is
demonstrated that a simple laser-diode technique with a single resonant light beam is sufficient to observe separately all
of the atomic hyperfine transitions of the D
2 line of Rb (780 nm) and also allows us to measure the relative transition probabilities of the hyperfine transitions. The
onset of collisional self-broadening of the hyperfine transitions as the number density of atoms increases was studied. The
detrimental role of the atoms with slow longitudinal velocity in the sub-Doppler response of the Rb ETC is demonstrated by
studies in which the cell is tilted from normal incidence of the laser beam. It is also shown that using an ETC allows us
to resolve in a moderate external magnetic field the Zeeman splitting of the hyperfine transitions of the 87Rb D
1 transition F
g=1F
e=1,2.
Received: 19 February 2003 / Revised version: 4 April 2003 / Published online: 2 June 2003
RID="*"
ID="*"Corresponding author. Fax: +374/32-31172, E-mail: david@ipr.sci.am 相似文献
16.
A. V. Derbin A. S. Kayunov V. N. Muratova 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(6):805-810
A search for the axioelectric absorption of 5.5-MeV solar axions produced in the p + d → 3He + γ (5.5 MeV) reaction was performed with two BGO detectors placed inside a low-background setup. Constraints on the axion-electron
coupling constant were obtained for axions with masses in the (0.1–1.0)-MeV range: g
Ae ≤ (1.8–9.0) × 10−7. The solar positron flux from A → e− + e+ decay was determined for axions with masses m
A
> 2m
e. Using the existing experimental data on the interplanetary positron flux, a new constraint on the axion-electron coupling
constant for axions with masses in the (1.2–5.4)-MeV range was obtained: g
Ae ≤ (1–5) × 10−17. 相似文献
17.
We investigate resonances in the pump-probe spectroscopy of Λ configuration of levels in the hyperfine manifold of D
2 transition of 133Cs and a7Rb with specific reference to Autler-Townes splitting, dressed state resonances in double Λ system and electromagnetically induced transparency. As an application, a dark resonance based magnetometer is briefly discussed. 相似文献
18.
Geol Moon 《Optics Communications》2008,281(2):294-298
We have studied the nonstationary effects in saturated absorption spectroscopy of the 87Rb D2 line. Varying the size of the σ+ polarized pump laser beam, we observed saturated absorption spectra for the σ± polarized probe beam. For equal polarizations of the pump and probe beams, we found that the resonance signal for the Fg = 1 → Fe = 2 line, and the crossover lines between Fg = 1 → Fe = 2 and Fg = 1 → Fe = 1 (and 0) lines increased to a greater extent than the others. This observation can be understood from the calculated time evolution of the populations of the ground-state sublevels by means of a rate equation model. We also compared experimental data for other conditions with the calculated results. We found good agreement between the calculated results and the data. 相似文献
19.
We calculated and studied the quantum coherence effects of a degenerate transition Fg = 3 ↔ Fe = 2 system interacting with a weak linearly polarized (with σ± components) probe light and a strong linearly polarized (with σ± components) coupling field. Due to the competition between the drive Rabi frequency and the Zeeman splitting, electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) are appeared at the different values of applied magnetic field in both cases that the Zeeman splitting of excited state Δe is smaller than the Zeeman splitting of ground state Δg (i.e., Δe < Δg) and Δe > Δg. It is shown that the resonance is broader and contrasts are higher for Δe < Δg than that for Δe > Δg at the same Rabi frequencies of probe and coupling fields. 相似文献
20.
H. Li H. Chen M. A. Gubin Y. V. Rostovtsev V. A. Sautenkov M. O. Scully 《Laser Physics》2010,20(8):1725-1728
We have studied electromagnetically induced transparency (EIT) in diatomic cesium molecules in a vapor cell by using tunable
diode lasers. We have observed a sub-natural Λ-resonance in absorption molecular band B
1Π
u
− X
1Σ
g
+ at different cesium vapor pressures. The width of the EIT resonance shows a linear dependence on a cesium vapor pressure. 相似文献