Carol Tanner - Academia.edu (original) (raw)

Papers by Carol Tanner

arXiv (Cornell University), Nov 14, 2023

We report a new precision measurement of the dc Stark shift of the 6s 2 S 1/2 → 7s 2 S 1/2 transi... more We report a new precision measurement of the dc Stark shift of the 6s 2 S 1/2 → 7s 2 S 1/2 transition in atomic cesium-133. Our result is 0.72246 (29) Hz(V/cm) −2. This result differs from a previous measurement of the Stark shift by ∼0.5%. We use this value to recalculate the magnitude of the reduced dipole matrix elements ⟨7s||r||7pj⟩, as well as the vector transition polarizability for the 6s → 7s transition,β = 27.043 (36) a 3 0. This determination helps resolve a critical discrepancy between two techniques for determining the vector polarizability.

Surface Science, Aug 1, 1982

Electronic structures of several atomic wires on an H-terminated Si͑100͒2ϫ1 surface have been exa... more Electronic structures of several atomic wires on an H-terminated Si͑100͒2ϫ1 surface have been examined by using first-principles calculations within the local-density-functional approach. Several dangling-bond ͑DB͒ wires, which are constructed by extracting H atoms from the surface, have been examined and found to have different characteristics depending on their structures. Electronic states near the Fermi energy are localized around the wire on the atomic scale in DB wires along the dimer rows on the surface, while they are much more delocalized around a DB wire in the direction across the dimer rows. Ga adsorbate atomic wires, which are formed by Ga adsorbates around the above wires, have also been examined. Several metastable geometries of Ga adsorbates were found. It was found that formation of Ga dimers was stable on this surface.

APS, May 1, 2019

We report measurements of the electric dipole matrix elements of the 133 Cs 6s 2 S 1/2 → 7p 2 P 1... more We report measurements of the electric dipole matrix elements of the 133 Cs 6s 2 S 1/2 → 7p 2 P 1/2 and 6s 2 S 1/2 → 7p 2 P 3/2 transitions. Each of these determinations is based on direct, precise comparisons of the absorption coefficients between two absorption lines. For the 6s 2 S 1/2 ||r||7p 2 P 3/2 matrix element, we measure the ratio of the absorption coefficient on this line with that of the D1 transition, 6s 2 S 1/2 → 6p 2 P 1/2. The matrix element of the D1 line has been determined with high precision previously by many groups. For the 6s 2 S 1/2 ||r||7p 2 P 1/2 matrix element, we measure the ratio of the absorption coefficient on this line with that of the 6s 2 S 1/2 → 7p 2 P 3/2 transition. Our results for these matrix elements are 6s 2 S 1/2 ||r||7p 2 P 3/2 = 0.57417 (57) a0 and 6s 2 S 1/2 ||r||7p 2 P 1/2 = 0.27810 (45) a0. These measurements have implications for the interpretation of parity nonconservation in atoms.

WORLD SCIENTIFIC eBooks, 2008

The amplitude of the parity-nonconserving transition between the 6S and 7S states of cesium was p... more The amplitude of the parity-nonconserving transition between the 6S and 7S states of cesium was precisely measured with the use of a spin-polarized atomic beam. This measurement gives Im(E1 pnc)/␤ ϭ Ϫ1.5935(56) millivolts per centimeter and provides an improved test of the standard model at low energy, including a value for the S parameter of Ϫ1.3(3) exp (11) theory. The nuclear spin-dependent contribution was 0.077(11) millivolts per centimeter; this contribution is a manifestation of parity violation in atomic nuclei and is a measurement of the long-sought anapole moment.

Physical Review A, 2004

Optical frequencies of the hyperfine components of the D 2 line in 133 Cs are determined using hi... more Optical frequencies of the hyperfine components of the D 2 line in 133 Cs are determined using high-resolution spectroscopy and a femtosecond laser frequency comb. A narrow-linewidth probe laser excites the 6s 2 S 1/2 ͑F =3,4͒ → 6p 2 P 3/2 ͑F =2,3,4,5͒ transition in a highly collimated atomic beam. Fluorescence spectra are taken by scanning the laser frequency over the excited-state hyperfine structure. The laser optical frequency is referenced to a Cs fountain clock via a reference laser and a femtosecond laser frequency comb. A retroreflected laser beam is used to estimate and minimize the Doppler shift due to misalignment between the probe laser and the atomic beam. We achieve an angular resolution on the order of 5 ϫ 10 −6 rad. The final uncertainties ͑ϳ ± 5 kHz͒ in the frequencies of the optical transitions are a factor of 20 better than previous results [T. Udem et al., Phys. Rev. A 62, 031801 (2000).]. We find the centroid of the 6s 2 S 1/2 → 6p 2 P 3/2 transition to be f D2 = 351 725 718.4744͑51͒ MHz.

Physical Review A, 2006

High resolution laser spectroscopy of the 6s 2 S 1/2 → 6p 2 P 1/2 transition ͑D 1 line͒ in neutra... more High resolution laser spectroscopy of the 6s 2 S 1/2 → 6p 2 P 1/2 transition ͑D 1 line͒ in neutral 133 Cs is performed in a highly collimated thermal atomic beam by use of a femtosecond laser frequency comb and narrow-linewidth diode laser. The diode laser is offset locked to a single frequency component of the femtosecond laser frequency comb and probes the optical transitions between selected pairs of ground-state and excited-state hyperfine components. A photodiode detects the excited-state decay fluorescence, and a computerized data acquisition system records the signal. The Doppler shift is eliminated by orienting the laser beam in a direction perpendicular to the atomic beam to within a precision of 5 ϫ 10 −6 rad. Optical frequencies for all four pairs of hyperfine components are measured independently, from which the D 1 line centroid and excitedstate hyperfine splitting are obtained by least-squares minimization with the ground-state splitting as a fixed constraint. We find the D 1 line centroid to be f D 1 = 335 116 048 748.1͑2.4͒ kHz, and the 6p 2 P 1/2 state hyperfine splitting to be 1 167 723.6͑4.8͒ kHz. These results, in combination with the results of an atom interferometry experiment by Wicht et al. ͓Phys. Scripta T 102, 82 ͑2002͔͒, are used to calculate a new value for the fine-structure constant.

WORLD SCIENTIFIC eBooks, 2008

Using a potassium niobate crystal in a modified self-locking power-buildup cavity, we have freque... more Using a potassium niobate crystal in a modified self-locking power-buildup cavity, we have frequency doubled the 865-nm output from a GaAlAs laser diode. With 12.4 mW of input power we have obtained a unidirectional output of 0.215 mW at 432 nm. In contrast to previous diode doubling experiments, the output was both single frequency and circular Gaussian. With better optics, substantially higher conversion efficiencies should be possible using this technique.

We have demonstrated a self-locking power-buildup cavity for laser diodes. This device requires o... more We have demonstrated a self-locking power-buildup cavity for laser diodes. This device requires only a few simple optical elements and can provide a standing wave containing as much as 1000 times the power emitted by the laser diode. With this device we have obtained an intense standing wave of tunable light that was used to collimate a cesium atomic beam. We have studied the power and frequency dependence of the beam collimation.

Physical Review A, Mar 15, 2006

Proceedings of SPIE, Apr 9, 2001

The saturated absorption spectrum of D2 line in Cs was investigated using two diode lasers emitti... more The saturated absorption spectrum of D2 line in Cs was investigated using two diode lasers emitting at 852nm. It was obtained in a 5cm long Cs cell at room temperature. The frequency scale was calibrated using the beat note signal from a fast photodetector on which the two laser beams were combined. In order to eliminate the effect of the reference laser frequency drift, a two-laser beam optical arrangement producing the saturated absorption was used. A simple model giving the number of observed peaks and the frequency intervals between them was developed. The two spectra corresponding to the two ground state components of Cs were fitted using a Lorentz profile as a model function and the obtained frequency intervals were compared with the Cs atom hyperfine splittings.

Physical review, Jan 10, 2023

We report measurements of the hyperfine coupling constant for the 8p 2 P 1/2 level of atomic cesi... more We report measurements of the hyperfine coupling constant for the 8p 2 P 1/2 level of atomic cesium, 133 Cs, with a relative uncertainty of ∼0.019%. Our result is A = 42.933 (8) MHz, in good agreement with recent theoretical results. We also examine the hyperfine structure of the 8p 2 P 3/2 state, and derive new values for the state energies of the 8p 2 P 1/2 and 8p 2 P 3/2 states of cesium.

Physica Status Solidi B-basic Solid State Physics, Mar 1, 1982

The transferability of norm-conserving pseudopotentials, recently developed by Hamann, Chiang and... more The transferability of norm-conserving pseudopotentials, recently developed by Hamann, Chiang and Schluter is examined by calculating static atomic polarizabilities using Sternheimers procedure. Excellent agreement between full-core atoms and pseudo-atoms confirm the high quality of norm-conserving pseudopotentials. Die Transferierbnrkeit von normerhaltenden Pseudopotentialen, die kiirzlich von Hammn, Cbiang und Schluter entwickelt murden, werden durch Berechnung der statischen Atom-Polarisierbarkeiten mit der Methode von Sternheimer untersucht. Die exzeliente Ubereinstimmung zwischen den vollstandigen Atomen und Pseudoatomen bestgtigt die hohe Qualitat der normrrhaltenden Pseudopotentide. l) 600 Mountain Avenue, Murray Hill, Kew Jersey 07 974, USA. ?) Bell Laboratories Summer Research Associate.

Physical review, Feb 22, 2022

We report measurements of the absolute energies of the hyperfine components of the 12s 2 S 1/2 an... more We report measurements of the absolute energies of the hyperfine components of the 12s 2 S 1/2 and 13s 2 S 1/2 levels of atomic cesium, 133 Cs. Using the frequency difference between these components, we determine the hyperfine coupling constants for these states, and report these values with a relative uncertainty of ∼0.06%. We also examine the hyperfine structure of the 11d 2 DJ (J = 3/2, 5/2) states, and resolve the sign ambiguity of the hyperfine coupling constants from previous measurements of these states. We also derive new, high precision values for the state energies of the 12s 2 S 1/2 , 13s 2 S 1/2 and 11d 2 DJ states of cesium.

Physical Review A, Mar 8, 2006

High resolution laser spectroscopy of the 6s 2 S 1/2 → 6p 2 P 1/2 transition ͑D 1 line͒ in neutra... more High resolution laser spectroscopy of the 6s 2 S 1/2 → 6p 2 P 1/2 transition ͑D 1 line͒ in neutral 133 Cs is performed in a highly collimated thermal atomic beam by use of a femtosecond laser frequency comb and narrow-linewidth diode laser. The diode laser is offset locked to a single frequency component of the femtosecond laser frequency comb and probes the optical transitions between selected pairs of ground-state and excited-state hyperfine components. A photodiode detects the excited-state decay fluorescence, and a computerized data acquisition system records the signal. The Doppler shift is eliminated by orienting the laser beam in a direction perpendicular to the atomic beam to within a precision of 5 ϫ 10 −6 rad. Optical frequencies for all four pairs of hyperfine components are measured independently, from which the D 1 line centroid and excitedstate hyperfine splitting are obtained by least-squares minimization with the ground-state splitting as a fixed constraint. We find the D 1 line centroid to be f D 1 = 335 116 048 748.1͑2.4͒ kHz, and the 6p 2 P 1/2 state hyperfine splitting to be 1 167 723.6͑4.8͒ kHz. These results, in combination with the results of an atom interferometry experiment by Wicht et al. ͓Phys. Scripta T 102, 82 ͑2002͔͒, are used to calculate a new value for the fine-structure constant.

Annual Meeting Optical Society of America, 1989

Early experiments on ultracold optical molasses relied on time-of-flight and other ballistic tech... more Early experiments on ultracold optical molasses relied on time-of-flight and other ballistic techniques to measure the temperature of atoms released from the molasses.1,2 At the extremely low temperatures observed, the size of the molasses, the effects of gravity, the probe that detected the falling atoms, and the way in which the laser beams forming the molasses were turned off produced a large systematic uncertainty in the temperature determination. Here, we report a direct measurement of the Doppler width of the fluorescence spectrum of Na atoms still viscously confined in the molasses. We determined this spectrum using an optical heterodyne technique and we believe this to be the first time an atomic fluorescence spectrum has been heterodyned. The temperature deduced from the Doppler width is in good agreement with that determined using improved time-of-flight techniques. The heterodyne technique has the added advantage of providing spatially resolved temperature measurements. In addition to the nominally 600-kHz wide Doppler peak, we see a much narrower (60-kHz wide) peak which we tentatively ascribe to Dicke narrowing due to confinement by optical forces.

The output of a mode-locked femtosecond laser is used for precision single-photon spectroscopy of... more The output of a mode-locked femtosecond laser is used for precision single-photon spectroscopy of 133Cs in an atomic beam. By changing the laser's repetition rate, the cesium D 1 (6s 2S1/2-+6p 2p1/2) and D 2 (6s 2S 1/2-+ 6p 2P3/2) transitions are detected and the optical frequencies are measured with accuracy similar to that obtained with a cw laser. Control of the femtosecond laser repetition rate by use of the atomic fluorescence is also implemented, thus realizing a simple cesium optical clock.

Bulletin of the American Physical Society, May 1, 1993

We report on progress made towards a direct measurement of the 6{sup 2}S{sub 1/2}{yields}7{sup 2}... more We report on progress made towards a direct measurement of the 6{sup 2}S{sub 1/2}{yields}7{sup 2}S{sub 1/2} Stark induced amplitude at 540 nm in atomic cesium. A precise measurement of this amplitude will provide an absolute calibration of atomic parity non-conservation experiments in Cs. The scalar and tensor transition measured via resonant absorption of linearly a gas cell with precisely known electric field and interaction length. The atomic number density required to scale the by measuring the Faraday anomalous dispersion of polarized light nearly resonant with the 6{sup 2}S{sub 1/2}{yields}6{sup 2}P{sub 3/2} 852 nm in a transition in a magnetic field. This technique requires precise knowledge of the 6{sup 2}S{sub 1/2}{yields}6{sup 2}P{sub 3/2} dipole matrix element which we have determined as part of our program of precision lifetime measurements.

We report measurements of the hyperfine coupling constant for the 8p 2 P 1/2 level of atomic cesi... more We report measurements of the hyperfine coupling constant for the 8p 2 P 1/2 level of atomic cesium, 133 Cs, with a relative uncertainty of ∼0.019%. Our result is A = 42.933 (8) MHz, in good agreement with recent theoretical results. We also examine the hyperfine structure of the 8p 2 P 3/2 state, and derive new values for the state energies of the 8p 2 P 1/2 and 8p 2 P 3/2 states of cesium.

arXiv (Cornell University), Nov 14, 2023

We report a new precision measurement of the dc Stark shift of the 6s 2 S 1/2 → 7s 2 S 1/2 transi... more We report a new precision measurement of the dc Stark shift of the 6s 2 S 1/2 → 7s 2 S 1/2 transition in atomic cesium-133. Our result is 0.72246 (29) Hz(V/cm) −2. This result differs from a previous measurement of the Stark shift by ∼0.5%. We use this value to recalculate the magnitude of the reduced dipole matrix elements ⟨7s||r||7pj⟩, as well as the vector transition polarizability for the 6s → 7s transition,β = 27.043 (36) a 3 0. This determination helps resolve a critical discrepancy between two techniques for determining the vector polarizability.

Surface Science, Aug 1, 1982

Electronic structures of several atomic wires on an H-terminated Si͑100͒2ϫ1 surface have been exa... more Electronic structures of several atomic wires on an H-terminated Si͑100͒2ϫ1 surface have been examined by using first-principles calculations within the local-density-functional approach. Several dangling-bond ͑DB͒ wires, which are constructed by extracting H atoms from the surface, have been examined and found to have different characteristics depending on their structures. Electronic states near the Fermi energy are localized around the wire on the atomic scale in DB wires along the dimer rows on the surface, while they are much more delocalized around a DB wire in the direction across the dimer rows. Ga adsorbate atomic wires, which are formed by Ga adsorbates around the above wires, have also been examined. Several metastable geometries of Ga adsorbates were found. It was found that formation of Ga dimers was stable on this surface.

APS, May 1, 2019

We report measurements of the electric dipole matrix elements of the 133 Cs 6s 2 S 1/2 → 7p 2 P 1... more We report measurements of the electric dipole matrix elements of the 133 Cs 6s 2 S 1/2 → 7p 2 P 1/2 and 6s 2 S 1/2 → 7p 2 P 3/2 transitions. Each of these determinations is based on direct, precise comparisons of the absorption coefficients between two absorption lines. For the 6s 2 S 1/2 ||r||7p 2 P 3/2 matrix element, we measure the ratio of the absorption coefficient on this line with that of the D1 transition, 6s 2 S 1/2 → 6p 2 P 1/2. The matrix element of the D1 line has been determined with high precision previously by many groups. For the 6s 2 S 1/2 ||r||7p 2 P 1/2 matrix element, we measure the ratio of the absorption coefficient on this line with that of the 6s 2 S 1/2 → 7p 2 P 3/2 transition. Our results for these matrix elements are 6s 2 S 1/2 ||r||7p 2 P 3/2 = 0.57417 (57) a0 and 6s 2 S 1/2 ||r||7p 2 P 1/2 = 0.27810 (45) a0. These measurements have implications for the interpretation of parity nonconservation in atoms.

WORLD SCIENTIFIC eBooks, 2008

The amplitude of the parity-nonconserving transition between the 6S and 7S states of cesium was p... more The amplitude of the parity-nonconserving transition between the 6S and 7S states of cesium was precisely measured with the use of a spin-polarized atomic beam. This measurement gives Im(E1 pnc)/␤ ϭ Ϫ1.5935(56) millivolts per centimeter and provides an improved test of the standard model at low energy, including a value for the S parameter of Ϫ1.3(3) exp (11) theory. The nuclear spin-dependent contribution was 0.077(11) millivolts per centimeter; this contribution is a manifestation of parity violation in atomic nuclei and is a measurement of the long-sought anapole moment.

Physical Review A, 2004

Optical frequencies of the hyperfine components of the D 2 line in 133 Cs are determined using hi... more Optical frequencies of the hyperfine components of the D 2 line in 133 Cs are determined using high-resolution spectroscopy and a femtosecond laser frequency comb. A narrow-linewidth probe laser excites the 6s 2 S 1/2 ͑F =3,4͒ → 6p 2 P 3/2 ͑F =2,3,4,5͒ transition in a highly collimated atomic beam. Fluorescence spectra are taken by scanning the laser frequency over the excited-state hyperfine structure. The laser optical frequency is referenced to a Cs fountain clock via a reference laser and a femtosecond laser frequency comb. A retroreflected laser beam is used to estimate and minimize the Doppler shift due to misalignment between the probe laser and the atomic beam. We achieve an angular resolution on the order of 5 ϫ 10 −6 rad. The final uncertainties ͑ϳ ± 5 kHz͒ in the frequencies of the optical transitions are a factor of 20 better than previous results [T. Udem et al., Phys. Rev. A 62, 031801 (2000).]. We find the centroid of the 6s 2 S 1/2 → 6p 2 P 3/2 transition to be f D2 = 351 725 718.4744͑51͒ MHz.

Physical Review A, 2006

High resolution laser spectroscopy of the 6s 2 S 1/2 → 6p 2 P 1/2 transition ͑D 1 line͒ in neutra... more High resolution laser spectroscopy of the 6s 2 S 1/2 → 6p 2 P 1/2 transition ͑D 1 line͒ in neutral 133 Cs is performed in a highly collimated thermal atomic beam by use of a femtosecond laser frequency comb and narrow-linewidth diode laser. The diode laser is offset locked to a single frequency component of the femtosecond laser frequency comb and probes the optical transitions between selected pairs of ground-state and excited-state hyperfine components. A photodiode detects the excited-state decay fluorescence, and a computerized data acquisition system records the signal. The Doppler shift is eliminated by orienting the laser beam in a direction perpendicular to the atomic beam to within a precision of 5 ϫ 10 −6 rad. Optical frequencies for all four pairs of hyperfine components are measured independently, from which the D 1 line centroid and excitedstate hyperfine splitting are obtained by least-squares minimization with the ground-state splitting as a fixed constraint. We find the D 1 line centroid to be f D 1 = 335 116 048 748.1͑2.4͒ kHz, and the 6p 2 P 1/2 state hyperfine splitting to be 1 167 723.6͑4.8͒ kHz. These results, in combination with the results of an atom interferometry experiment by Wicht et al. ͓Phys. Scripta T 102, 82 ͑2002͔͒, are used to calculate a new value for the fine-structure constant.

WORLD SCIENTIFIC eBooks, 2008

Using a potassium niobate crystal in a modified self-locking power-buildup cavity, we have freque... more Using a potassium niobate crystal in a modified self-locking power-buildup cavity, we have frequency doubled the 865-nm output from a GaAlAs laser diode. With 12.4 mW of input power we have obtained a unidirectional output of 0.215 mW at 432 nm. In contrast to previous diode doubling experiments, the output was both single frequency and circular Gaussian. With better optics, substantially higher conversion efficiencies should be possible using this technique.

We have demonstrated a self-locking power-buildup cavity for laser diodes. This device requires o... more We have demonstrated a self-locking power-buildup cavity for laser diodes. This device requires only a few simple optical elements and can provide a standing wave containing as much as 1000 times the power emitted by the laser diode. With this device we have obtained an intense standing wave of tunable light that was used to collimate a cesium atomic beam. We have studied the power and frequency dependence of the beam collimation.

Physical Review A, Mar 15, 2006

Proceedings of SPIE, Apr 9, 2001

The saturated absorption spectrum of D2 line in Cs was investigated using two diode lasers emitti... more The saturated absorption spectrum of D2 line in Cs was investigated using two diode lasers emitting at 852nm. It was obtained in a 5cm long Cs cell at room temperature. The frequency scale was calibrated using the beat note signal from a fast photodetector on which the two laser beams were combined. In order to eliminate the effect of the reference laser frequency drift, a two-laser beam optical arrangement producing the saturated absorption was used. A simple model giving the number of observed peaks and the frequency intervals between them was developed. The two spectra corresponding to the two ground state components of Cs were fitted using a Lorentz profile as a model function and the obtained frequency intervals were compared with the Cs atom hyperfine splittings.

Physical review, Jan 10, 2023

We report measurements of the hyperfine coupling constant for the 8p 2 P 1/2 level of atomic cesi... more We report measurements of the hyperfine coupling constant for the 8p 2 P 1/2 level of atomic cesium, 133 Cs, with a relative uncertainty of ∼0.019%. Our result is A = 42.933 (8) MHz, in good agreement with recent theoretical results. We also examine the hyperfine structure of the 8p 2 P 3/2 state, and derive new values for the state energies of the 8p 2 P 1/2 and 8p 2 P 3/2 states of cesium.

Physica Status Solidi B-basic Solid State Physics, Mar 1, 1982

The transferability of norm-conserving pseudopotentials, recently developed by Hamann, Chiang and... more The transferability of norm-conserving pseudopotentials, recently developed by Hamann, Chiang and Schluter is examined by calculating static atomic polarizabilities using Sternheimers procedure. Excellent agreement between full-core atoms and pseudo-atoms confirm the high quality of norm-conserving pseudopotentials. Die Transferierbnrkeit von normerhaltenden Pseudopotentialen, die kiirzlich von Hammn, Cbiang und Schluter entwickelt murden, werden durch Berechnung der statischen Atom-Polarisierbarkeiten mit der Methode von Sternheimer untersucht. Die exzeliente Ubereinstimmung zwischen den vollstandigen Atomen und Pseudoatomen bestgtigt die hohe Qualitat der normrrhaltenden Pseudopotentide. l) 600 Mountain Avenue, Murray Hill, Kew Jersey 07 974, USA. ?) Bell Laboratories Summer Research Associate.

Physical review, Feb 22, 2022

We report measurements of the absolute energies of the hyperfine components of the 12s 2 S 1/2 an... more We report measurements of the absolute energies of the hyperfine components of the 12s 2 S 1/2 and 13s 2 S 1/2 levels of atomic cesium, 133 Cs. Using the frequency difference between these components, we determine the hyperfine coupling constants for these states, and report these values with a relative uncertainty of ∼0.06%. We also examine the hyperfine structure of the 11d 2 DJ (J = 3/2, 5/2) states, and resolve the sign ambiguity of the hyperfine coupling constants from previous measurements of these states. We also derive new, high precision values for the state energies of the 12s 2 S 1/2 , 13s 2 S 1/2 and 11d 2 DJ states of cesium.

Physical Review A, Mar 8, 2006

High resolution laser spectroscopy of the 6s 2 S 1/2 → 6p 2 P 1/2 transition ͑D 1 line͒ in neutra... more High resolution laser spectroscopy of the 6s 2 S 1/2 → 6p 2 P 1/2 transition ͑D 1 line͒ in neutral 133 Cs is performed in a highly collimated thermal atomic beam by use of a femtosecond laser frequency comb and narrow-linewidth diode laser. The diode laser is offset locked to a single frequency component of the femtosecond laser frequency comb and probes the optical transitions between selected pairs of ground-state and excited-state hyperfine components. A photodiode detects the excited-state decay fluorescence, and a computerized data acquisition system records the signal. The Doppler shift is eliminated by orienting the laser beam in a direction perpendicular to the atomic beam to within a precision of 5 ϫ 10 −6 rad. Optical frequencies for all four pairs of hyperfine components are measured independently, from which the D 1 line centroid and excitedstate hyperfine splitting are obtained by least-squares minimization with the ground-state splitting as a fixed constraint. We find the D 1 line centroid to be f D 1 = 335 116 048 748.1͑2.4͒ kHz, and the 6p 2 P 1/2 state hyperfine splitting to be 1 167 723.6͑4.8͒ kHz. These results, in combination with the results of an atom interferometry experiment by Wicht et al. ͓Phys. Scripta T 102, 82 ͑2002͔͒, are used to calculate a new value for the fine-structure constant.

Annual Meeting Optical Society of America, 1989

Early experiments on ultracold optical molasses relied on time-of-flight and other ballistic tech... more Early experiments on ultracold optical molasses relied on time-of-flight and other ballistic techniques to measure the temperature of atoms released from the molasses.1,2 At the extremely low temperatures observed, the size of the molasses, the effects of gravity, the probe that detected the falling atoms, and the way in which the laser beams forming the molasses were turned off produced a large systematic uncertainty in the temperature determination. Here, we report a direct measurement of the Doppler width of the fluorescence spectrum of Na atoms still viscously confined in the molasses. We determined this spectrum using an optical heterodyne technique and we believe this to be the first time an atomic fluorescence spectrum has been heterodyned. The temperature deduced from the Doppler width is in good agreement with that determined using improved time-of-flight techniques. The heterodyne technique has the added advantage of providing spatially resolved temperature measurements. In addition to the nominally 600-kHz wide Doppler peak, we see a much narrower (60-kHz wide) peak which we tentatively ascribe to Dicke narrowing due to confinement by optical forces.

The output of a mode-locked femtosecond laser is used for precision single-photon spectroscopy of... more The output of a mode-locked femtosecond laser is used for precision single-photon spectroscopy of 133Cs in an atomic beam. By changing the laser's repetition rate, the cesium D 1 (6s 2S1/2-+6p 2p1/2) and D 2 (6s 2S 1/2-+ 6p 2P3/2) transitions are detected and the optical frequencies are measured with accuracy similar to that obtained with a cw laser. Control of the femtosecond laser repetition rate by use of the atomic fluorescence is also implemented, thus realizing a simple cesium optical clock.

Bulletin of the American Physical Society, May 1, 1993

We report on progress made towards a direct measurement of the 6{sup 2}S{sub 1/2}{yields}7{sup 2}... more We report on progress made towards a direct measurement of the 6{sup 2}S{sub 1/2}{yields}7{sup 2}S{sub 1/2} Stark induced amplitude at 540 nm in atomic cesium. A precise measurement of this amplitude will provide an absolute calibration of atomic parity non-conservation experiments in Cs. The scalar and tensor transition measured via resonant absorption of linearly a gas cell with precisely known electric field and interaction length. The atomic number density required to scale the by measuring the Faraday anomalous dispersion of polarized light nearly resonant with the 6{sup 2}S{sub 1/2}{yields}6{sup 2}P{sub 3/2} 852 nm in a transition in a magnetic field. This technique requires precise knowledge of the 6{sup 2}S{sub 1/2}{yields}6{sup 2}P{sub 3/2} dipole matrix element which we have determined as part of our program of precision lifetime measurements.

We report measurements of the hyperfine coupling constant for the 8p 2 P 1/2 level of atomic cesi... more We report measurements of the hyperfine coupling constant for the 8p 2 P 1/2 level of atomic cesium, 133 Cs, with a relative uncertainty of ∼0.019%. Our result is A = 42.933 (8) MHz, in good agreement with recent theoretical results. We also examine the hyperfine structure of the 8p 2 P 3/2 state, and derive new values for the state energies of the 8p 2 P 1/2 and 8p 2 P 3/2 states of cesium.