We demonstrate Ramsey spectroscopy with cold 87 Rb atoms via a two-photon Raman process. One laser beam has a cross-over resonant frequency on the 85 Rb transition and the other beam has a 6.8 GHz shifted frequency. These two laser beams fulfill the two-photon Raman resonance condition, which involves a single-photon detuning of −2.6 GHz. By implementing these two lasers on cold 87 Rb atoms, we demonstrate Ramsey spectroscopy with an interrogation time of the intermediate state by using π /2 Raman pulses. In our laser system, we can change the single-photon detuning to 1.2, 4.2 or −5.6 GHz by changing the 85 Rb transition line used as a locking signal and an injected sideband. The laser system that directly uses resonant light on isotope atoms will be described in this paper.We demonstrate Ramsey spectroscopy with cold 87 Rb atoms via a two-photon Raman process. One laser beam has a cross-over resonant frequency on the 85 Rb transition and the other beam has a 6.8 GHz shifted frequency. These two laser beams fulfill the two-photon Raman resonance condition, which involves a single-photon detuning of −2.6 GHz. By implementing these two lasers on cold 87 Rb atoms, we demonstrate Ramsey spectroscopy with an interrogation time of the intermediate state by using π /2 Raman pulses. In our laser system, we can change the single-photon detuning to 1.2, 4.2 or −5.6 GHz by changing the 85 Rb transition line used as a locking signal and an injected sideband. The laser system that directly uses resonant light on isotope atoms will be described in this paper.

Journal of the Korean Physical SocietyMar 1, 20140 citations

Studies of Raman Transitions in Cold Atoms in Arbitrary Magnetic Fields

Frank A. Narducci, J.C. Davis, Emily Clifton +2 more

Bulletin of the American Physical SocietyJun 17, 20110 citations

Double resonance spectroscopy of laser-cooled Rb atoms

Alastair G. Sinclair, Barry D. McDonald, Erling Riis +1 more

Optics CommunicationsMar 1, 199427 citations

Phase Stabilized Diode Laser Frequencies for Raman Beam Generation

- Anju, Aishik Acharya

The advancement of cold atom gravimeters (CAG) is based on the precise control and stabilization of lasers used for the atom interferometry.The 5S → 5P transition in rubidium (Rb) at 780.241 nm is crucial for such quantum technology applications.In this study, the hyperfine structure of 5 2 S1/2 → 5 2 P3/2, D2 transition line of 87 Rb atoms obtained through saturation absorption spectroscopy, are used as a reference for the frequency stabilization of an external cavity diode laser (ECDL) operating at 780 nm.The ECDL is locked to the hyperfine saturated absorption peak of 87 Rb (F = 2 → 3').This laser beam is combined with another 780 nm ECDL laser to obtain the beat frequency spectrum, generating a beat note signal of ~ 6.8 GHz, which is needed for phase stabilization between lasers.These are critical for the Raman beam generation in the CAG, as the 87 Rb atoms ground hyperfine states (F = 1 and F = 2) have separation of ~ 6.834 GHz, and two Raman beams with an 6.8 GHz offset can drive transitions between these hyperfine states of 87 Rb to realize the CAG interferometry scheme.The advancement of cold atom gravimeters (CAG) is based on the precise control and stabilization of lasers used for the atom interferometry.The 5S → 5P transition in rubidium (Rb) at 780.241 nm is crucial for such quantum technology applications.In this study, the hyperfine structure of 5 2 S1/2 → 5 2 P3/2, D2 transition line of 87 Rb atoms obtained through saturation absorption spectroscopy, are used as a reference for the frequency stabilization of an external cavity diode laser (ECDL) operating at 780 nm.The ECDL is locked to the hyperfine saturated absorption peak of 87 Rb (F = 2 → 3').This laser beam is combined with another 780 nm ECDL laser to obtain the beat frequency spectrum, generating a beat note signal of ~ 6.8 GHz, which is needed for phase stabilization between lasers.These are critical for the Raman beam generation in the CAG, as the 87 Rb atoms ground hyperfine states (F = 1 and F = 2) have separation of ~ 6.834 GHz, and two Raman beams with an 6.8 GHz offset can drive transitions between these hyperfine states of 87 Rb to realize the CAG interferometry scheme.

URSI Regional Conference on Radio Science (URSI-RCRS)Jan 1, 20240 citations

Isotopic effect on collisional widths and shifts of Hg clock transition induced by cold Rb atoms

Renu Bala, A. Linek, Marcin Witkowski +4 more

We study the isotopic dependence of collisional widths and shifts of the Hg clock transition $^1$ S $_0$ - $^3$ P $_0$ perturbed by the Rb atoms in the temperature range from 1 nK to 1 K. For this purpose, we model the Born-Oppenheimer effective interaction potential by including the leading long-range van der Waals coefficients. For elastic collisions, we show the connection between the dependence of collision line shape parameters on the reduced mass of colliding partners as well as the variation of the scattering length in the excited and ground states of the Hg-Rb system in the $\upmu$K temperature range. We confront the full quantum scattering calculations with a semi-classical approximation for collisional widths and shifts. We show that the shape resonances in excited and ground scattering states lead to significant variations of collisional line shape parameters with the change of the reduced mass of colliding atoms. We also indicate the possible influence of inelastic collisions, which could lead to universal behavior and significantly affect the dependence of collisional broadening and shifting on the isotopic combination of colliding atoms.We study the isotopic dependence of collisional widths and shifts of the Hg clock transition $^1$S$_0$-$^3$P$_0$ perturbed by the Rb atoms in the temperature range from 1 nK to 1 K. For this purpose, we model the Born-Oppenheimer effective interaction potential by including the leading long-range van der Waals coefficients. For elastic collisions, we show the connection between the dependence of collision line shape parameters on the reduced mass of colliding partners as well as the variation of the scattering length in the excited and ground states of the Hg-Rb system in the $\upmu$K temperature range. We confront the full quantum scattering calculations with a semi-classical approximation for collisional widths and shifts. We show that the shape resonances in excited and ground scattering states lead to significant variations of collisional line shape parameters with the change of the reduced mass of colliding atoms. We also indicate the possible influence of inelastic collisions, which could lead to universal behavior and significantly affect the dependence of collisional broadening and shifting on the isotopic combination of colliding atoms.

arXiv:2605.01908May 3, 20260 citations

Atom Counting by Hyperfine Raman Optical Pumping in Cold Rubidium 87

Joshua A. Carter, Brent Manley Jones, S.J. Roof +4 more

Bulletin of the American Physical SocietyMay 28, 20190 citations

Determination of the Raman Transition in Cold

^{87}

Rb Atoms by Using an Isotope Transition Line

We study the isotopic dependence of collisional widths and shifts of the Hg clock transition

^1

_0

^3

_0

perturbed by the Rb atoms in the temperature range from 1 nK to 1 K. For this purpose, we model the Born-Oppenheimer effective interaction potential by including the leading long-range van der Waals coefficients. For elastic collisions, we show the connection between the dependence of collision line shape parameters on the reduced mass of colliding partners as well as the variation of the scattering length in the excited and ground states of the Hg-Rb system in the $\upmu$K temperature range. We confront the full quantum scattering calculations with a semi-classical approximation for collisional widths and shifts. We show that the shape resonances in excited and ground scattering states lead to significant variations of collisional line shape parameters with the change of the reduced mass of colliding atoms. We also indicate the possible influence of inelastic collisions, which could lead to universal behavior and significantly affect the dependence of collisional broadening and shifting on the isotopic combination of colliding atoms.