Velocity selection in a Doppler-broadened ensemble of atoms interacting with a monochromatic laser beam

Hughes, Ifan G.

doi:10.1080/09500340.2017.1328749

Cited by 8 publications

(13 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The distribution of velocities within our atom cloud, measured by Raman velocimetry (2.5 mW per Raman beam for 100 µs), is shown in Figure 4, and fits well a Gaussian distribution with a temperature of 21 µK superimposed upon a broad background that we have previously attributed to inhomogeneous sub-Doppler cooling [4 , 24 ]. This velocimetry method is itself subject to inaccuracies, and at longer exposure times yields higher temperatures, perhaps for the reasons discussed in [19 ]. Figure 5 shows the in-phase and quadrature interferometer traces, C(T ) and S(T ), for our atom cloud.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Matterwave interferometric velocimetry of cold Rb atoms

Carey

Belal

Himsworth

et al. 2017

Journal of Modern Optics

View full text Add to dashboard Cite

We consider the matterwave interferometric measurement of atomic velocities, which forms a building block for all matterwave inertial measurements. A theoretical analysis, addressing both the laboratory and atomic frames and accounting for residual Doppler sensitivity in the beamsplitter and recombiner pulses, is followed by an experimental demonstration, with measurements of the velocity distribution within a 20 µK cloud of rubidium atoms. Our experiments use Raman transitions between the long-lived ground hyperfine states, and allow quadrature measurements that yield the full complex interferometer signal and hence discriminate between positive and negative velocities. The technique is most suitable for measurement of colder samples. ARTICLE HISTORY

show abstract

Section: Resultsmentioning

confidence: 99%

“…Unlike conventional c.w. spectroscopy, however, measurements of velocities in the wings of the distribution are not distorted by weak interactions with more numerous atoms [19 ].…”

Section: Interferometric Velocimetrymentioning

confidence: 99%

Matterwave interferometric velocimetry of cold Rb atoms

Carey

Belal

Himsworth

et al. 2017

Journal of Modern Optics

View full text Add to dashboard Cite

show abstract

“…The astute reader will notice that the Fourier transform of the signal defined in Equation (5) can only be measured experimentally for positive pulse separations τ , and that the signal is thus effectively multiplied by a Heaviside step function. With ideal interferometer pulses that perform perfect, instantaneous operations upon all atoms ( Figure 1a) this would introduce an orthogonal component to the Fourier transform that could be separated from the velocity information, but in practice deconvolution becomes intractable because pulses of finite duration ( Figure 1b) themselves exhibit Doppler sensitivity, introducing a velocity-dependent amplitude and phase shift that we have explored in more detail in [27].…”

Section: A Mach-zehnder Interferometer For Atom Velocimetrymentioning

confidence: 99%

“…Popular methods of measuring velocity distributions, such as time-of-flight imaging [3], Raman [4,5] and Bragg [6,7] Doppler spectroscopy, rely upon separate interactions with small slices of the velocity distribution to build up a complete measurement. Each involves the signal from only a small number of atoms, and there are artefacts from the initial cloud size and measurement-induced perturbation of the velocity distribution.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Velocimetry of cold atoms by matter-wave interferometry

et al. 2019

View full text Add to dashboard Cite

We present an elegant application of matterwave interferometry to the velocimetry of cold atoms whereby, in analogy to Fourier transform spectroscopy, the 1-D velocity distribution is manifest in the frequency domain of the interferometer output. By using stimulated Raman transitions between hyperfine ground states to perform a three-pulse interferometer sequence, we have measured the velocity distributions of clouds of freely-expanding 85 Rb atoms with temperatures of 34 µK and 18 µK. Quadrature measurement of the interferometer output as a function of the temporal asymmetry yields velocity distributions with excellent fidelity. Our technique, which is particularly suited to ultracold samples, compares favourably with conventional Doppler and time-of-flight techniques, and reveals artefacts in standard Raman Doppler methods. The technique is related to, and provides a conceptual foundation of, interferometric matterwave accelerometry, gravimetry and rotation sensing.

show abstract

Electromagnetically induced transparency in a V-system with ⁸⁷Rb vapour in the hyperfine Paschen-Back regime

Higgins

Hughes

2021

J. Phys. B: At. Mol. Opt. Phys.

Self Cite

View full text Add to dashboard Cite

We observe electromagnetically induced transparency (EIT) in a V-system in a thermal rubidium-87 vapour in the hyperfine Paschen-Back regime, realised with a 0.6 T axial magnetic field. In this regime energy levels are no longer degenerate and EIT features from different initial states are distinct, which we show produces a much cleaner feature than without a magnetic field. We compare our results to a model using the time-dependent Lindblad master equation, and having averaged over a distribution of interaction times, see good qualitative agreement for a range of pump Rabi frequencies. Excited state decay into both ground states is shown to play a prominent role in the generation of the transparency feature, which arises mainly due to transfer of population into the ground state not coupled by the probe beam. We use the model to investigate the importance of coherence in this feature, showing that its contribution is more significant at smaller pump Rabi frequencies.

show abstract

Velocity selection in a Doppler-broadened ensemble of atoms interacting with a monochromatic laser beam

Cited by 8 publications

References 52 publications

Matterwave interferometric velocimetry of cold Rb atoms

Matterwave interferometric velocimetry of cold Rb atoms

Velocimetry of cold atoms by matter-wave interferometry

Electromagnetically induced transparency in a V-system with ⁸⁷Rb vapour in the hyperfine Paschen-Back regime

Contact Info

Product

Resources

About

Velocity selection in a Doppler-broadened ensemble of atoms interacting with a monochromatic laser beam

Cited by 8 publications

References 52 publications

Matterwave interferometric velocimetry of cold Rb atoms

Matterwave interferometric velocimetry of cold Rb atoms

Velocimetry of cold atoms by matter-wave interferometry

Electromagnetically induced transparency in a V-system with 87Rb vapour in the hyperfine Paschen-Back regime

Contact Info

Product

Resources

About

Electromagnetically induced transparency in a V-system with ⁸⁷Rb vapour in the hyperfine Paschen-Back regime