Atomic Coherence Effects in Quantum Optics.

The control of the optical properties of a medium by atomic coherence and quantum interference effects is an important area of research, not only for its fundamental aspects in the understanding of radiation and matter interaction, but also for its potential applications in the design of optical devices. Atomic coherence can emerge in a medium through the coupling of a strong coherent field to an atomic transition. This coupling affects the optical properties of the medium in a very interesting ways. For example, it may yield light amplification without population inversion. Also, it can modify the traditional dispersion of an optical medium in such a way that maximum variations of the refractive index occur around a spectral region of vanishing absorption. In the first part of this work we investigate some fundamental aspects of this coherent dynamics. We investigate how this non-inversion gain is affected by the presence of atomic motion. The coherent interaction between atom and radiation can lead to the interference between optical paths of decay. We report on an atomic setting where the interference structures depend upon the phase of the coherent field, an new effect which is absent in other resonance fluorescent phenomena. As a potential application, we investigate a novel approach for the modulation of optical signal. This approach consists of injecting atomic coherence in the medium in order to tailor its optical properties so it is a more suitable medium for modulation.The control of the optical properties of a medium by atomic coherence and quantum interference effects is an important area of research, not only for its fundamental aspects in the understanding of radiation and matter interaction, but also for its potential applications in the design of optical devices. Atomic coherence can emerge in a medium through the coupling of a strong coherent field to an atomic transition. This coupling affects the optical properties of the medium in a very interesting ways. For example, it may yield light amplification without population inversion. Also, it can modify the traditional dispersion of an optical medium in such a way that maximum variations of the refractive index occur around a spectral region of vanishing absorption. In the first part of this work we investigate some fundamental aspects of this coherent dynamics. We investigate how this non-inversion gain is affected by the presence of atomic motion. The coherent interaction between atom and radiation can lead to the interference between optical paths of decay. We report on an atomic setting where the interference structures depend upon the phase of the coherent field, an new effect which is absent in other resonance fluorescent phenomena. As a potential application, we investigate a novel approach for the modulation of optical signal. This approach consists of injecting atomic coherence in the medium in order to tailor its optical properties so it is a more suitable medium for modulation.

Jan 1, 19970 citations

Coherence and Quantum Optics

Richard M. Sillitto

Optica Acta International Journal of OpticsJan 1, 1974118 citations

Coherence and Quantum Optics

R.W. Smith

Optica Acta International Journal of OpticsOct 1, 197956 citations

Quantum sensitivity limits of an optical magnetometer based on atomic phase coherence

Michael Fleischhauer, Marlan O. Scully

An optical magnetometer based on atomic coherence effects is analyzed using a quantum Langevin approach. The large dispersion of a phase-coherent atomic medium (``phaseonium'') at a point of vanishing absorption is used to detect magnetic level shifts via optical phase measurements in a Mach-Zehnder interferometer with sensitivities potentially superior to state-of-the-art devices. Effects of Doppler broadening and fluctuations of the driving field are discussed and a comparison to standard optical-pumping magnetometers is made.An optical magnetometer based on atomic coherence effects is analyzed using a quantum Langevin approach. The large dispersion of a phase-coherent atomic medium (``phaseonium'') at a point of vanishing absorption is used to detect magnetic level shifts via optical phase measurements in a Mach-Zehnder interferometer with sensitivities potentially superior to state-of-the-art devices. Effects of Doppler broadening and fluctuations of the driving field are discussed and a comparison to standard optical-pumping magnetometers is made.

Physical Review AMar 1, 1994142 citations

Coherence and Quantum Optics

L. Mandeļ, E. Wolf

Springer eBooksJan 1, 197387 citations

Time-reversed and coherently enhanced memory: A single-mode quantum atom-optic memory without a cavity

Jesse L. Everett, Pierre Vernaz-Gris, Geoff Campbell +5 more

The efficiency of an ensemble-based optical quantum memory depends critically on the strength of the atom-light coupling. An optical cavity is an effective method to enhance atom-light coupling strength, with the drawback that cavities can be difficult to integrate into a memory setup. In this work we show coherent enhancement of atom-light coupling via an interference effect. The light to be absorbed into the atomic ensemble is split and used to drive the atoms from opposite ends of the ensemble. We compare this method theoretically to a cavity-enhanced scheme and present experimental results for our coherent enhancement in cold $^{87}\mathrm{Rb}$ atoms that show an efficiency of $72\ifmmode\pm\else\textpm\fi{}5%$ and a storage lifetime of $110\ifmmode\pm\else\textpm\fi{}10\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\text{s}$.The efficiency of an ensemble-based optical quantum memory depends critically on the strength of the atom-light coupling. An optical cavity is an effective method to enhance atom-light coupling strength, with the drawback that cavities can be difficult to integrate into a memory setup. In this work we show coherent enhancement of atom-light coupling via an interference effect. The light to be absorbed into the atomic ensemble is split and used to drive the atoms from opposite ends of the ensemble. We compare this method theoretically to a cavity-enhanced scheme and present experimental results for our coherent enhancement in cold $^{87}\mathrm{Rb}$ atoms that show an efficiency of $72\ifmmode\pm\else\textpm\fi{}5%$ and a storage lifetime of $110\ifmmode\pm\else\textpm\fi{}10\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\text{s}$.

arXiv:1901.07144Physical Review ADec 28, 201811 citations

^{87}\mathrm{Rb}

atoms that show an efficiency of $72\ifmmode\pm\else\textpm\fi{}5%$ and a storage lifetime of $110\ifmmode\pm\else\textpm\fi{}10\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\text{s}$.