Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Optics Letters

Stabilization of a microwave oscillator using a resonance Raman transition in a sodium beam

Philip Hemmer, C. C. Leiby, Shaoul Ezekiel

Published Aug 1, 1983• 72 citations
Publisher

Abstract

Preliminary results on the stabilization of a 1772-MHz oscillator to a resonance Raman transition in an atomic beam of sodium are presented. Short-term stability of 5.6 x 10(-11) (tau = 100 sec) for a 15-cm Ramsey interaction-region separation has been achieved. Sources of frequency drift are briefly discussed.
DOI
10.1364/ol.8.000440

Related papers

Precision studies of stimulated-resonance Raman interactions in an atomic beam

Philip Hemmer, G. P. Ontai, Shaoul Ezekiel

Precision studies of stimulated-resonance Raman interactions in a sodium atomic beam were performed with emphasis on Ramsey’s separated-field excitation. Ramsey fringes were obtained for a field separation of up to 30 cm, and the data were consistent with theoretical predictions. Possible applications of this Raman interaction to clock development also were studied by stabilizing a microwave oscillator to a Raman–Ramsey fringe. The resulting oscillator stability of 1.5 × 10−11 for a 1000-sec averaging time compares favorably with commercial cesium clocks when differences in atom transit time and transition frequency are taken into consideration. Finally, potential sources of long-term frequency error, which are important for clock applications, were also partially investigated.

Journal of the Optical Society of America B•Feb 1, 1986•55 citations

Performance of a Microwave Clock Based on a Laser-Induced Stimulated Raman Interactions

Philip Hemmer, Shaoul Ezekiel, C. C. Leiby

Recent experimental work1 has demonstrated that a microwave oscillator can be stabilized using a stimulated-resonance Raman transition in a sodium atomic beam. This Raman technique is of interest because optical lasers rather than microwaves are used in the interaction, and, aside from fundamental interest, the greater flexibility of optical systems may make it possible eventually to develop more-stable and moreportable atomic clocks.

•Jun 18, 1984•2 citations

Observation of Ramsey Fringes Using a Stimulated, Resonance Raman Transition in a Sodium Atomic Beam

John E. Thomas, Philip Hemmer, Shaoul Ezekiel +3 more

Ramsey fringes have been observed using a stimulated, resonance Raman transition at 1772 MHz excited by two dye lasers in a sodium atomic beam. The width of the central fringe is 650 Hz (half width at half maximum), corresponding to a 30-cm interaction-region separation. The fringes are free from laser jitter because the jitters in both laser beams are correlated. Applications to frequency standards as well as to high-resolution spectroscopy in the microwave to far-ir regions are discussed.

Physical Review Letters•Mar 29, 1982•219 citations

Semiconductor laser excitation of Ramsey fringes by using a Raman transition in a cesium atomic beam

Philip Hemmer, M. S. Shahriar, B. E. Bernacki +3 more

An amplitude-modulated semiconductor laser is used to excite a 9.2-GHz Raman transition in a cesium atomic beam. Separated-field Ramsey fringes as narrow as 1 kHz wide are observed with a high signal-to-noise ratio, even for semiconductor laser linewidths as wide as 20 MHz. These narrow resonances have potential application in the development of high-accuracy, optically excited atomic clocks.

Journal of the Optical Society of America B•Aug 1, 1993•47 citations

Progress toward a Raman-Ramsey Clock Based on a Transverse Cooled Rubidium Beam

Pei-Qiang Yan, Weichen Jia, Yanying Feng

SummaryIn this paper we reported our progress toward an atomic beam clock based on a transverse cooled rubidium beam. The atomic beam is generated from an atomic oven and collimated via micro-channel arrays and a two-dimensional optical lattice. After optical pumping, the rubidium beam interacts with two spatially separated Raman beams with a π/2 − π/2 sequence. High contrast Raman-Ramsey fringes are observed by using fluorescence detection. Preliminary result shows that the estimated frequency stability of the atomic clock reaches $2.6 \times {10^{ - 11}}/\sqrt \tau $. The atomic beam clock is proposed as a part of atomic beam inertial navigation unit for field applications.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•May 15, 2023•0 citations

A microwave amplitude stabilization method for atomic clocks with Ramsey interrogation

Michele Gozzelino, Salvatore Micalizio, Filippo Levi +2 more

We describe a method to stabilize the amplitude of the interrogating microwave field in compact atomic clocks working in a Ramsey approach. In this technique, we take advantage of the pulsed regime to use the atoms themselves as microwave amplitude discriminators. Specifically, in addition to the dependence on the microwave detuning, the atomic signal after the Ramsey interrogation acquires a dependence on the microwave pulse area (amplitude times duration) that can be exploited to implement an active stabilization of the microwave field amplitude, in a similar way in which the Ramsey clock signal is used to lock the local oscillator frequency to the atomic reference. This stabilization results in a reduced sensitivity of the clock frequency to microwave amplitude fluctuations that are transferred to the atoms through the cavity-pulling effect. The proposed technique is then effective to improve the clock stability and drift on medium and long term. We demonstrate the method for a vapor-cell clock working with a hot sample of atoms but it can be extended to cold-atom compact clocks.

•Feb 9, 2018•0 citations
Precision studies of stimulated-resonance Raman interactions in a sodium atomic beam were performed with emphasis on Ramsey’s separated-field excitation. Ramsey fringes were obtained for a field separation of up to 30 cm, and the data were consistent with theoretical predictions. Possible applications of this Raman interaction to clock development also were studied by stabilizing a microwave oscillator to a Raman–Ramsey fringe. The resulting oscillator stability of 1.5 × 10−11 for a 1000-sec averaging time compares favorably with commercial cesium clocks when differences in atom transit time and transition frequency are taken into consideration. Finally, potential sources of long-term frequency error, which are important for clock applications, were also partially investigated.
SummaryIn this paper we reported our progress toward an atomic beam clock based on a transverse cooled rubidium beam. The atomic beam is generated from an atomic oven and collimated via micro-channel arrays and a two-dimensional optical lattice. After optical pumping, the rubidium beam interacts with two spatially separated Raman beams with a π/2 − π/2 sequence. High contrast Raman-Ramsey fringes are observed by using fluorescence detection. Preliminary result shows that the estimated frequency stability of the atomic clock reaches $2.6 \times {10^{ - 11}}/\sqrt \tau $. The atomic beam clock is proposed as a part of atomic beam inertial navigation unit for field applications.
We describe a method to stabilize the amplitude of the interrogating microwave field in compact atomic clocks working in a Ramsey approach. In this technique, we take advantage of the pulsed regime to use the atoms themselves as microwave amplitude discriminators. Specifically, in addition to the dependence on the microwave detuning, the atomic signal after the Ramsey interrogation acquires a dependence on the microwave pulse area (amplitude times duration) that can be exploited to implement an active stabilization of the microwave field amplitude, in a similar way in which the Ramsey clock signal is used to lock the local oscillator frequency to the atomic reference. This stabilization results in a reduced sensitivity of the clock frequency to microwave amplitude fluctuations that are transferred to the atoms through the cavity-pulling effect. The proposed technique is then effective to improve the clock stability and drift on medium and long term. We demonstrate the method for a vapor-cell clock working with a hot sample of atoms but it can be extended to cold-atom compact clocks.