Measurements of vector magnetic field using multiple electromagnetically induced transparency resonances in Rb vapor

We study intensity distribution of transmission resonances under the conditions of electromagnetically induced transparency (EIT) with lin||lin configuration in 87Rb vapor. We demonstrate that for various orientations of the external magnetic field all seven resolved EIT resonances exhibit maxima or minima at certain directions of the linear polarization of the laser field. This effect can be used for development of a high-precision vector EIT magnetometer.Comment: 4 pages, 4 figure

Measurements of the magnetic field vector using multiple electromagnetically induced transparency resonances in Rb vapor

We study the dependence of electromagnetically induced transparency (EIT) resonance amplitudes on the external magnetic field direction in a linearly polarized bichromatic light (lin||lin) configuration in (87)Rb vapor. We demonstrate that all seven resolvable EIT resonances exhibit maxima or minima at certain orientations of the laser polarization relative to the wave vector and magnetic field. This effect can be used for the development of a high- precision EIT vector magnetometer

Coherent population trapping resonances with linearly polarized light for all-optical miniature atomic clocks

We present a joint theoretical and experimental characterization of the coherent population trapping (CPT) resonance excited on the D1 line of 87Rb atoms by bichromatic linearly polarized laser light. We observe high-contrast transmission resonances (up to 25%), which makes this excitation scheme promising for miniature all-optical atomic clock applications. We also demonstrate cancellation of the first-order light shift by proper choice of the frequencies and relative intensities of the two laser field components. Our theoretical predictions are in good agreement with the experimental results.Comment: 8 pages, 7 figure

Generalised hyper-Ramsey resonance with spinors

PAPER PRESENTED AT THE VIII SYMPOSIUM 'MPLP-2018'International audienceThe generalized hyper-Ramsey resonance formula originally published in Phys. Rev. A vol 92, 023416 (2015) is derived using a Cayley-Klein spinor parametrization. The shape of the interferometric resonance and the associated composite phase-shift are reformulated including all individual laser pulse parameters. Potential robustness of signal contrast and phase-shift of the wave-function fringe pattern can now be arbitrarily explored tracking any shape distortion due to systematic effects from the probe laser. An exact and simple analytical expression describing a Ramsey's method of separated composite oscillating laser fields with quantum state control allows us to accurately simulate all recent clock interrogation protocols under various pulse defects

Peculiar long-term fluorescence of Rb atoms in a coated vapor cell

We report on an experiment in which the decay time of an oscillating fluorescence of rubidium atoms on a 5P state in a coated vapor cell exceeds several of milliseconds; that is, many orders of magnitude longer than the normal decay time of the excited atoms. We found that the amplitude of this peculiar feature with long-term decay strongly depends to which particular atomic ground sublevels of the Rb atom and to which particular Rb isotopes are used and it could be clearly observed in a high-quality cell only. All these cases are characterized by a sufficiently long lifetime of optically pumped atoms on a sublevel of Rb atom ground state. A numerical simulation based on a complete density matrix developed for the case of two intense pumping and probing laser fields interacting with low density Rb vapor is presented. The model supports the coherent coupling process of a population on excited level to the correspondingly long-lived population on the ground-state sublevel by both probing and pumping radiations as the most plausible mechanism to explain the observed spectacular phenomenon

Light-Shift Suppression with Novel Variants of Adaptive Ramsey Spectroscopy

International audienceWe present a brief review of the rapidly growing field of autobalanced Ramsey spectroscopy followed by a detailed discussion and review of two novel techniques that were developed and tested in our laboratory: displaced frequency-jump Ramsey spectroscopy and combined error signal spectroscopy. These two techniques are related to, yet different from autobalanced Ramsey spectroscopy. The use of these techniques in a cold-atom clock based on coherent population trapping has reduced instabilities from variations in light-shift parameters by at least one order of magnitude. In each of these techniques the Ramsey sequence adapts to cancel light shifts and drifts

Protocol for light-shift compensation in a continuous-wave microcell atomic clock

International audienceLight-shifts are known to be an important limitation to the mid- and long-term fractional frequency stability of different types of atomic clocks.In this article, we demonstrate the experimental implementation of an anti-light shift interrogation protocol onto a continuous-wave (CW) microcell atomic clock based on coherent population trapping (CPT). The method, inspired by the Auto-Balanced Ramsey (ABR) spectroscopy technique demonstrated in pulsed atomic clocks, consists in the extraction of atomic-based information from two successive light-shifted clock frequencies obtained at two different laser power values. Two error signals, computed from the linear combination of signals acquired along a symmetric sequence, are managed in a dual-loop configuration to generate a clock frequency free from light-shift. Using this method, the sensitivity of the clock frequency to both laser power and microwave power variations can be reduced by more than an order of magnitude compared to normal operation. In the present experiment, the consideration of the non-linear light-shift dependence allowed to enhance light-shift mitigation. The implemented technique allows an improvement of the clock Allan deviation for time scales higher than 1000 s. This method could be applied in various kinds of atomic clocks such as CPT-based atomic clocks, double-resonance Rb clocks, or cell-stabilized lasers

Corrigendum: Composite laser-pulses spectroscopy for high-accuracy optical clocks: a review of recent progress and perspectives (2018 Rep. Prog. Phys . 81 094401)

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General methods for suppressing the light shift in atomic clocks using power modulation

International audienceWe show that the light shift in atomic clocks can be suppressed using time variation of the interrogation field intensity. By measuring the clock output at two intensity levels, error signals can be generated that simultaneously stabilize a local oscillator to an atomic transition and correct for the shift of this transition caused by the interrogating optical field. These methods are suitable for optical clocks using one- andtwo-photon transitions, as well as for microwave clocks based on coherent population trapping or direct interrogation. The proposed methods can be widely used both for high-precision scientific instruments and for a wide range of commercial clocks, including chip-scale atomic clocks