We report an experimental demonstration of photon switching by quantum interference in a four-level atomic system proposed by Harris and Yamamoto [Phys. Rev. Lett. 81, 3611 (1998)]. Quantum interference inhibits single-photon absorption but enhances third-order, two-photon-type absorption in the four-level system. We have observed greatly enhanced nonlinear absorption in the four-level system realized with cold ${}^{87}\mathrm{Rb}$ atoms and demonstrated fast switching of the nonlinear absorption with a pulsed pump laser.We report an experimental demonstration of photon switching by quantum interference in a four-level atomic system proposed by Harris and Yamamoto [Phys. Rev. Lett. 81, 3611 (1998)]. Quantum interference inhibits single-photon absorption but enhances third-order, two-photon-type absorption in the four-level system. We have observed greatly enhanced nonlinear absorption in the four-level system realized with cold ${}^{87}\mathrm{Rb}$ atoms and demonstrated fast switching of the nonlinear absorption with a pulsed pump laser.

arXiv:physics/0105065Physical Review ASep 12, 2001193 citations

Theoretical analysis on two-photon absorption spectroscopy in a confined four-level atomic system

李院院 Yuanyuan Li, Jintao Bai, 李莉 Li Li +2 more

We investigate theoretically two-photon absorption spectroscopy modified by a control field in a confined Y-type four-level system. Dicke-narrowing effect occurs both in two-photon absorption lines and the dips of transparency against two-photon absorption due to enhanced contribution of slow atoms. We also find that the suppression and the enhancement of two-photon absorption call be modified by changing the strength of the control field and the detuning of three laser fields. This control of two-photon absorption may have some applications in information processing and optical devices.We investigate theoretically two-photon absorption spectroscopy modified by a control field in a confined Y-type four-level system. Dicke-narrowing effect occurs both in two-photon absorption lines and the dips of transparency against two-photon absorption due to enhanced contribution of slow atoms. We also find that the suppression and the enhancement of two-photon absorption call be modified by changing the strength of the control field and the detuning of three laser fields. This control of two-photon absorption may have some applications in information processing and optical devices.

Chinese Optics LettersJan 1, 20090 citations

Separated subsystems in four-level atom

Zhifang Deng

Optics CommunicationsDec 1, 198318 citations

Analytical solution of a three-level atom coupled to four systems of N-two-level atoms

D. A. M. Abo-Kahla, M. M. A. Ahmed, A. T. M. Makram-Allah

Optical ReviewOct 29, 20197 citations

Investigation of Electromagnetically Induced Absorption

Fangyi Liu

Electromagnetically induced absorption(EIA) is an intriguing phenomenon of light-atom interaction.The study of its nonlinear behaviors has theoretical significance and potential applications.On the basis of the researches of degenerate two-level system,N-type four-level system and quasi degenerate N-type level system,the forming mechanism and creating conditions of EIA are given.The result that destructive interference of atomic coherence leads to electromagnetically induced absorption is shown.Furthermore,the dramatic change of dispersion line in the corresponding frequency occurs in the anomalous dispersion,which can be used to realize speeding up of the light group velocity or negative group velocity.The applications of EIA are being further studied.Electromagnetically induced absorption(EIA) is an intriguing phenomenon of light-atom interaction.The study of its nonlinear behaviors has theoretical significance and potential applications.On the basis of the researches of degenerate two-level system,N-type four-level system and quasi degenerate N-type level system,the forming mechanism and creating conditions of EIA are given.The result that destructive interference of atomic coherence leads to electromagnetically induced absorption is shown.Furthermore,the dramatic change of dispersion line in the corresponding frequency occurs in the anomalous dispersion,which can be used to realize speeding up of the light group velocity or negative group velocity.The applications of EIA are being further studied.

Journal of Hebei UniversityJan 1, 20100 citations

{}^{87}\mathrm{Rb}

atoms and demonstrated fast switching of the nonlinear absorption with a pulsed pump laser.