Laser Physics Letters

The effects of degeneracy of atomic levels on single‐photon emission via Raman scattering

Решетов Владимир Александрович, Igor V. Yevseyev

Published May 4, 2008• 2 citations

Abstract

The three-level Λ-type atom with degenerate atomic levels is considered, one of its transitions being driven by the coherent field, the other being coupled to the single-mode quantized field of the high-Q cavity. The probability of emission of a single photon in the cavity via Raman scattering versus the mutual orientation of polarization vectors of the cavity mode and of the driving coherent pulse is studied. The efficiency of the retrieval of a single-photon excitation, stored in the atomic ground state (as suggested, e.g., in paper [1]), versus the mutual orientation of polarizations of cavity modes and of the coherent ``write'' and ``read'' pulses is also investigated. The numerical calculations are carried out for the transitions between hyperfine components of the ground 6 S 1/2 and excited 6 P 3/2 states of Cesium atoms, which were exploited in the experiments [1]. The optimal polarizations providing the maximum probability of photon emission and maximum retrieval efficiency are determined.

DOI: 10.1002/lapl.200810041

Related papers

Photon emission by an atom with degenerate levels into a micro-cavity with polarization-degenerate mode

Решетов Владимир Александрович

Abstract The emission of a photon by an atom with degenerate levels into a micro-cavity with a single polarization-degenerate mode is studied theoretically with an account of irreversible relaxation of the atom–field system for the atomic excitation by a short laser pulse as well as by means of vacuum-stimulated Raman adiabatic passage. The analytic expressions for the probability of emission of the photon in the cavity and for the photon polarization matrix are derived in the ’strong-coupling’ and ‘bad-cavity’ approximations for arbitrary values of angular momenta of atomic levels. The dependence of the photon polarization on the polarization of the control laser field is studied. It is shown that the degree of photon polarization may be varied from zero (maximum atom–photon entanglement) to unity (disentangled atom and photon) by means of the control-field polarization.

Laser PhysicsJun 22, 20201 citation

Polarization properties of Raman micromaser

Решетов Владимир Александрович, И. Н. Пигалева, Igor V. Yevseyev

The polarization properties of one-atom maser pumped by the coherent field via Raman transitions are studied theoretically. The three-level Λ-type atoms with degenerate Rydberg levels E b < E a < E c enter the micromaser cavity being excited to the lower level E b . The coherent microwave field drives the transition b → c , while the maser transition a → c is coupled to the cavity quantum field. The dependence of the maser field parameters, such as the mean photon number and the variance, as well as of the correlation functions of the atoms, emerging from the cavity, versus the angle ψ between the polarizations of the maser and driving fields are investigated. The case of transitions J b = 3/2 → J c = 3/2 and J a = 5/2 → J c = 3/2 in the rubidium atoms, which are exploited in micromaser experiments (see, e.g., the review [1]), is analyzed numerically. The possibility of monitoring the state of the maser field by means of driving field polarization is discussed.

Laser Physics LettersDec 12, 20080 citations

Single photons made-to-measure

Genko S Vasilev, Daniel Ljunggren, Axel Kuhn

We investigate the efficiency of atom-cavity-based photon-generation schemes to deliver single photons of arbitrary temporal shape. Our model applies to Raman transitions in three-level atoms with one branch of the transition driven by a laser pulse and the other coupled to a cavity mode. For any possible shape of the single-photon wavepacket, we derive an unambiguous analytic expression for the shape of the required driving laser pulse. Furthermore, we discuss the constraints limiting the maximum probability for emitting any desired photon, and use these to estimate upper bounds for the efficiency of the process. The model is not only valid for vacuum-stimulated Raman adiabatic passages (V-STIRAP) in the strong-coupling and bad-cavity regime, but also generally allows the control of the coherence and population flow in any Raman process.

arXiv:0907.0761New Journal of PhysicsJun 14, 201083 citations

Single Photons Made-to-Measure

G. S. Vasilev, Daniel Ljunggren, Axel Kuhn

We investigate the efficiency of atom-cavity based photon-generation schemes to deliver single photons of arbitrary temporal shape. Our model applies to Raman transitions in three-level atoms with one branch of the transition driven by a laser pulse, and the other coupled to a cavity mode. For any possible shape of the single-photon wavepacket, we derive an unambiguous analytic expression for the shape of the required driving laser pulse. We furthermore discuss the constraints limiting the maximum probability for emitting any desired photon, and use these to estimate upper bounds for the efficiency of the process. The model is not only valid for Vacuum-Stimulated Raman Adiabatic Passages (V-STIRAP) in the strong-coupling and bad-cavity regime, but it generally allows controlling the coherence and population flow in any Raman process.

Aug 15, 201640 citations

The dynamics of an atom-field system with degenerate atomic levels and a polarization-degenerate mode of the quantised field in a damped micro-cavity

Решетов Владимир Александрович

Abstract The master equation for the atom-field system with degenerate atomic levels and two polarization modes of the quantized field in a damped micro-cavity is obtained in the basis of eigenvectors of the interaction operator. The solution for the lossless cavity is obtained. The analytic expressions for the probability of emission of the photon in the cavity by an excited atom and of the photon polarization matrix are derived in the ‘strong coupling’ and ‘bad cavity’ approximations for arbitrary values of angular momenta of atomic levels. The dependence of the photon polarization on the polarization of the short excitation pulse is studied.

Laser Physics LettersJan 9, 20202 citations

Semiclassical and quantum nonlinear spectra of a strongly coupled single Λ-type three-level atom-cavity QED system

Mohamed Musa, Helmi Temimi, Y. Zhu

We present detailed numerical simulations of semiclassical and quantum spectra of a cavity QED system consisting of a single three-level atom in Λ-configuration interacting with a quantized cavity mode through one of its transitions while its other transition is driven by a coherent classical field. We compute the semiclassical and quantum spectra of the system under various levels of external driving field strengths. In the semiclassical approach, we neglect the correlations between the cavity and atomic operators, whereas in the quantum case no such assumption is made. Our results show that the two approaches yield identical results under sufficiently weak driving field conditions. However, the two approaches yield starkly different results at stronger driving field intensities: the fully quantum approach yields a well-defined multiphoton spectrum whereas the semiclassical approach results in a bistable spectrum. Furthermore, our calculations reveal a complex Raman structure at the position of the dark-state transition.

arXiv:1907.12391Journal of Modern OpticsMar 4, 20221 citation