Coherent laser spectroscopy of rubidium atoms
08 Oct 2010-Vol. 7747, pp 86-94
TL;DR: In this paper, the authors used two or three external cavity diode lasers to study multiple resonance transitions in Λ-and V-type systems as well as on (Λ+V)-type system.
Abstract: Laser spectroscopy experiments are reported on rubidium atoms by using two or three external cavity diode lasers to
study multiple resonance transitions in Λ- and V-type systems as well as on (Λ+V)-type system. Electromagnetically
induced transparency (EIT) peaks having sub-natural line-widths are found on the Doppler broadened transmission
backgrounds with velocity selective enhanced absorption dips. In the presence of a pump laser, probe spectrum shows
enhancement of EIT signal by tuning the control laser frequency when the Λ- and V-type EIT signals are made to
overlap. Theoretical analysis is carried out by solving the optical Bloch equations for five-level atomic model under Λ
configuration. With the numerically simulated spectra, variation of EIT transmission peak with ground state decay rate
and excited state spontaneous decay rate are investigated. Effect of pump Rabi frequency on the transmission peak is
also shown.
References
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TL;DR: In this paper, the authors examined coherent effects in a four-level Vee scheme and showed that the system can be made to display a number of different phenomena, including the inhibition of two-photon absorption and the production of multiple dark states.
Abstract: We examine coherent effects in a four-level Vee scheme. We show that the system can be made to display a number of different phenomena, including the inhibition of two-photon absorption and the production of multiple dark states. We show that this latter effect is due to the independent control of the Autler–Townes splitting of the upper and lower probe field by independent driving fields. We suggest possible experimental systems in rubidium for the observation of such effects.
46 citations
TL;DR: In this article, the authors reported theoretical studies of a Λ-type five-level atomic system, where the density matrix equations were set up and solved numerically to obtain the probe absorption line shape of Rb D2 transitions for cold and room temperature atoms.
Abstract: We report theoretical studies of a Λ-type five-level atomic system. The density matrix equations are set up and solved numerically to obtain the probe absorption line shape of Rb D2 transitions for cold (Doppler-free) and room temperature (Doppler-broadened) atoms. Simulated spectra for Doppler-broadened systems lead to four velocity-selective dips along with an electromagnetic induced transparency (EIT) peak as observed earlier from the co-propagating pump–probe spectroscopy of Rb D2 transitions. Effects of pump power and spontaneous decay rate from the upper levels on the simulated spectra are also studied. For cold atoms a very pronounced EIT peak is observed when the pump frequency is on resonance with one allowed transition. We find that lower pump power leads to a much sharper EIT signal in this case. A simulated dispersion curve shows a rapid variation of the refractive index that may lead to a sharp reduction of the group velocity of photons.
36 citations
TL;DR: In this paper, it was shown that the pump-probe spectroscopy of Λ-type system for the D2 transition of 87Rb exhibits additional absorption enhancement peaks due to velocity selective optical pumping along with the electromagnetically induced transparency (EIT).
Abstract: It is shown that the pump-probe spectroscopy of Λ-type system for the D2 transition of 87Rb exhibits additional absorption enhancement peaks due to velocity selective optical pumping along with the electromagnetically induced transparency (EIT). The separation of these peaks is consistent with the hyperfine splitting of the upper levels. For 85Rb the peaks are not clearly discernible since the hyperfine splitting is much smaller.
30 citations
TL;DR: In this paper, a detailed analysis of the line shape of electromagnetically induced transparency (EIT) in a Doppler broadened five level atomic system based on density matrix formalism is presented.
25 citations
TL;DR: It is shown that strong-probe EIT has different linewidth and appears in fewer configurations than does usual, weak probe EIT, in V-scheme, where optical pumping and saturation are dominant mechanisms and narrow EIT is possible only when a probe is tuned to a closed transition.
Abstract: We have experimentally studied electromagnetically induced transparency (EIT) and absorption (EIA) in hot 85Rb atomic vapor using probe and coupling light with comparable power levels. We have shown that strong-probe EIT has different linewidth and appears in fewer configurations than does usual, weak probe EIT. In V-scheme, where optical pumping and saturation are dominant mechanisms, narrow EIT is possible only when a probe is tuned to a closed transition. The width of the EIT resonance increases with laser intensity with non-linear dependence, similar to the weak-probe EIT in Λ- scheme. The EIT in Λ- scheme was observed when two transitions had balanced population losses. The EIA was modified for the case of a strong probe as well: in four-level N-scheme with Zeeman sublevels the EIA was observed only for a cycling transition when F’=F+1, where F and F’ are the angular momenta of the 5 2S1/2 (ground) and 5 2P3/2 (excited) state hyper-fine levels, respectively. The combination of strong probe and strong coupling laser beam intensities allows observation of an absorption dip due to three-photon resonance in a four-level scheme that involves the Raman transitions via virtual level.
21 citations