We report on the first results with resonance enhanced two-photon spectroscopy of magnetically trapped atomic hydrogen, exciting the transition from the $1S$ ground state to the $3S$ or the $3D$ state. The spectroscopic method introduces tunable transparency to resonant optical studies of cold dense gases. It combines sensitivity (due to the near resonant $2P$ state) with high resolution (in principle limited only by the $3S$ state lifetime), making it a precision tool for optical investigation of ultracold H gas. To demonstrate its potential, the dynamic evolution of H gas during evaporative cooling is quantitatively investigated by analysis of two-photon absorption spectra.We report on the first results with resonance enhanced two-photon spectroscopy of magnetically trapped atomic hydrogen, exciting the transition from the $1S$ ground state to the $3S$ or the $3D$ state. The spectroscopic method introduces tunable transparency to resonant optical studies of cold dense gases. It combines sensitivity (due to the near resonant $2P$ state) with high resolution (in principle limited only by the $3S$ state lifetime), making it a precision tool for optical investigation of ultracold H gas. To demonstrate its potential, the dynamic evolution of H gas during evaporative cooling is quantitatively investigated by analysis of two-photon absorption spectra.

Physical Review LettersSep 29, 19977 citations

Quantum logic spectroscopy of atomic and molecular ions

Wan, Yong

Laser spectroscopy is a versatile tool to investigate the internal structure of atoms, molecules and nuclei.High precision spectroscopy requires laser cooling to reduce Doppler broadening and Doppler shifts.Sympathetic cooling extends these advantages to species which do not have an appropriate transition for laser cooling and allows precision spectroscopy of previously inaccessible species using the quantum logic technique.The original implementation of quantum logic spectroscopy relies on the long lifetime of the excited spectroscopy state to realize a transfer sequence.Precision spectroscopy of transitions with a short-lived excited state is typically performed using laser induced uorescence or laser absorption spectroscopy.Neither of these methods has reached the fundamental quantum projection noise limit and are rather limited by photon shot noise.For these situations, we develop the technique of photon recoil spectroscopy as an extension of quantum logic spectroscopy to broad transitions.The common motion of a sideband-cooled two-ion crystal is excited by photon recoil during photon absorption on the spectroscopically investigated ion.This motional excitation is transferred to an internal state excitation on the co-trapped ion of a dierent species and detected with high eciency.We demonstrate the technique on the 2 S 1/2 ↔ 2 P 1/2 transition of the 40 Ca + ion and resolve the line center to 1/300 of its observed linewidth.The simplicity and versatility of the technique promises applications to other previously inaccessible species.A variation of the technique is proposed for rotational state preparation of molecular ions.A moving optical lattice is employed to exert a state-dependent force on the molecule.This would allow the detection of the rotational state of the molecular ion and therefore enable precision spectroscopy of specic rovibrational transitions in the molecule.Laser spectroscopy is a versatile tool to investigate the internal structure of atoms, molecules and nuclei.High precision spectroscopy requires laser cooling to reduce Doppler broadening and Doppler shifts.Sympathetic cooling extends these advantages to species which do not have an appropriate transition for laser cooling and allows precision spectroscopy of previously inaccessible species using the quantum logic technique.The original implementation of quantum logic spectroscopy relies on the long lifetime of the excited spectroscopy state to realize a transfer sequence.Precision spectroscopy of transitions with a short-lived excited state is typically performed using laser induced uorescence or laser absorption spectroscopy.Neither of these methods has reached the fundamental quantum projection noise limit and are rather limited by photon shot noise.For these situations, we develop the technique of photon recoil spectroscopy as an extension of quantum logic spectroscopy to broad transitions.The common motion of a sideband-cooled two-ion crystal is excited by photon recoil during photon absorption on the spectroscopically investigated ion.This motional excitation is transferred to an internal state excitation on the co-trapped ion of a dierent species and detected with high eciency.We demonstrate the technique on the 2 S 1/2 ↔ 2 P 1/2 transition of the 40 Ca + ion and resolve the line center to 1/300 of its observed linewidth.The simplicity and versatility of the technique promises applications to other previously inaccessible species.A variation of the technique is proposed for rotational state preparation of molecular ions.A moving optical lattice is employed to exert a state-dependent force on the molecule.This would allow the detection of the rotational state of the molecular ion and therefore enable precision spectroscopy of specic rovibrational transitions in the molecule.

Jan 1, 20140 citations

Two-photon spectroscopy in a fast atomic beam

Rainer Salomaa, Stig Stenholm

Optics CommunicationsFeb 1, 197610 citations

Spectroscopy of francium

J. E. Simsarian, Joshua M. Grossman, Luis A. Orozco +3 more

Francium is the least studied of the alkali atoms because it has no stable isotopes. We have performed precision spectroscopy on cold Fr atoms in a magneto optical trap. We have determined the location of the first two excited states of the S series by two-photon spectroscopy. We have measured the lifetimes of the 7p levels with a precision better than 0.5%. Our measurements test the many-body perturbation theory ab initio calculations of the dipole matrix element to very high accuracy in this relativistic alkali.Francium is the least studied of the alkali atoms because it has no stable isotopes. We have performed precision spectroscopy on cold Fr atoms in a magneto optical trap. We have determined the location of the first two excited states of the S series by two-photon spectroscopy. We have measured the lifetimes of the 7p levels with a precision better than 0.5%. Our measurements test the many-body perturbation theory ab initio calculations of the dipole matrix element to very high accuracy in this relativistic alkali.

AIP conference proceedingsJan 1, 19991 citation

Two-photon spectroscopy of atoms and molecules

M. P. McCann, C. H. Chen, Marvin G. Payne

Conference on Lasers and Electro-OpticsApr 25, 19881 citation

We report on the first results with resonance enhanced two-photon spectroscopy of magnetically trapped atomic hydrogen, exciting the transition from the

1S

ground state to the

3S

or the

3D

state. The spectroscopic method introduces tunable transparency to resonant optical studies of cold dense gases. It combines sensitivity (due to the near resonant

2P

state) with high resolution (in principle limited only by the

3S

state lifetime), making it a precision tool for optical investigation of ultracold H gas. To demonstrate its potential, the dynamic evolution of H gas during evaporative cooling is quantitatively investigated by analysis of two-photon absorption spectra.