S. M. Rochester
University of Rochester
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Featured researches published by S. M. Rochester.
Reviews of Modern Physics | 2002
Dmitry Budker; W. Gawlik; D. F. Kimball; S. M. Rochester; Valeriy V. Yashchuk; Antoine Weis
In this article, we review the history, current status, physical mechanisms, experimental methods, and applications of nonlinear magneto-optical effects in atomic vapors. We begin by describing the pioneering work of Macaluso and Corbino over a century ago on linear magneto-optical effects (in which the properties of the medium do not depend on the light power) in the vicinity of atomic resonances, and contrast these effects with various nonlinear magneto-optical phenomena that have been studied both theoretically and experimentally since the late 1960s. In recent years, the field of nonlinear magneto-optics has experienced a revival of interest that has led to a number of developments, including the observation of ultra-narrow (1-Hz) magneto-optical resonances, applications in sensitive magnetometry, nonlinear magneto-optical tomography, and the possibility of a search for parity- and time-reversal-invariance violation in atoms.
Proceedings of the National Academy of Sciences of the United States of America | 2006
Shoujun Xu; Valeriy V. Yashchuk; Marcus H. Donaldson; S. M. Rochester; Dmitry Budker; Alexander Pines
We report an approach for the detection of magnetic resonance imaging without superconducting magnets and cryogenics: optical atomic magnetometry. This technique possesses a high sensitivity independent of the strength of the static magnetic field, extending the applicability of magnetic resonance imaging to low magnetic fields and eliminating imaging artifacts associated with high fields. By coupling with a remote-detection scheme, thereby improving the filling factor of the sample, we obtained time-resolved flow images of water with a temporal resolution of 0.1 s and spatial resolutions of 1.6 mm perpendicular to the flow and 4.5 mm along the flow. Potentially inexpensive, compact, and mobile, our technique provides a viable alternative for MRI detection with substantially enhanced sensitivity and time resolution for various situations where traditional MRI is not optimal.
Astronomy and Astrophysics | 2010
Ronald Holzlöhner; S. M. Rochester; D. Bonaccini Calia; Dmitry Budker; James Higbie; W. Hackenberg
Context. Sodium laser guide stars (LGS) are about to enter a new range of laser powers. Previous theoretical and numerical methods are inadequate for accurate computations of the return flux, hence for the design of the next-generation LGS systems. Aims. We numerically optimize the cw (continuous wave) laser format, in particular, the light polarization and spectrum. Methods. Using Bloch equations, we simulate the mesospheric sodium atoms, including Doppler broadening, saturation, collisional relaxation, Larmor precession, and recoil, taking all 24 sodium hyperfine states into account and 100–300 velocity groups. Results. LGS return flux is limited by “three evils”: Larmor precession due to the geomagnetic field, atomic recoil due to radiation pressure, and transition saturation. We study their impact and show that the return flux can be boosted by repumping (simultaneous excitation of the sodium D2 aa nd D 2b lines with 10−20% of the laser power in the latter). Conclusions. We strongly recommend the use of circularly polarized lasers and repumping. As a rule of thumb, the bandwidth of laser radiation in MHz (at each line) should approximately equal the launched laser power in Watts divided by six, assuming a diffraction-limited spot size.
Physical Review A | 2006
Victor M. Acosta; Micah P. Ledbetter; S. M. Rochester; Dmitry Budker; D. F. Jackson Kimball; D. C. Hovde; W. Gawlik; Szymon Pustelny; Jerzy Zachorowski; Valeriy V. Yashchuk
Recent work investigating resonant nonlinear magneto-opticalrotation (NMOR) related to long-lived (tau_rel approx 1s) ground-stateatomic coherences has demonstrated potential magnetometric sensitivitiesexceeding (10-11 G Hz-1/2) for small (<1 micro G) magnetic fields. Inthe present work, NMOR using frequency-modulated light (FM NMOR) isstudied in the regime where the longitudinal magnetic field is in thegeophysical range (sim 500mG), of particular interest for manyapplications. In this regime a splitting of the FM NMOR resonancedue tothe nonlinear Zeeman effect is observed. At sufficiently high lightintensities, there is also a splitting of the FM NMOR resonances due toac Stark shifts induced by the optical field, as well as evidence ofalignment-to-orientation conversion type processes. The consequences ofthese effects for FM-NMOR-based atomic magnetometry in the geophysicalfield range are considered.
Physical Review Letters | 2004
Valeriy V. Yashchuk; Josef Granwehr; D. F. Kimball; S. M. Rochester; Andreas H. Trabesinger; Jiri Urban; Dmitry Budker; Alexander Pines
We report the use of an atomic magnetometer based on nonlinear magneto-optical rotation with frequency-modulated light to detect nuclear magnetization of xenon gas. The magnetization of a spin-exchange-polarized xenon sample (1.7 c m(3) at a pressure of 5 bars, natural isotopic abundance, polarization 1% ), prepared remotely to the detection apparatus, is measured with an atomic sensor. An average magnetic field of approximately 10 nG induced by the xenon sample on the 10 cm diameter atomic sensor is detected with signal-to-noise ratio approximately 10 , limited by residual noise in the magnetic environment. The possibility of using modern atomic magnetometers as detectors of nuclear magnetic resonance and in magnetic resonance imaging is discussed. Atomic magnetometers appear to be ideally suited for emerging low-field and remote-detection magnetic resonance applications.
Review of Scientific Instruments | 2006
Shoujun Xu; S. M. Rochester; Valeriy V. Yashchuk; Marcus H. Donaldson; Dmitry Budker
We report on the design, characterization, and applications of a sensitive atomic magnetic gradiometer. The device is based on nonlinear magneto-optical rotation in alkali-metal (Rb87) vapor and uses frequency-modulated laser light. The magnetic field produced by a sample is detected by measuring the frequency of a resonance in optical rotation that arises when the modulation frequency equals twice the Larmor precession frequency of the Rb atoms. The gradiometer consists of two atomic magnetometers. The rotation of light polarization in each magnetometer is detected with a balanced polarimeter. The sensitivity of the gradiometer is 0.8nG∕Hz1∕2 for near-dc (0.1Hz) magnetic fields, with a base line of 2.5cm. For applications in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI), a long solenoid that pierces the magnetic shields provides an ∼0.5G leading field for the nuclear spins in the sample. Our apparatus is particularly suited for remote detection of NMR and MRI. We demonstrate a poi...
Physical Review Letters | 2004
M. Auzinsh; Dmitry Budker; D. F. Kimball; S. M. Rochester; J. E. Stalnaker; A. O. Sushkov; Valeriy V. Yashchuk
We consider the limitations due to noise (e.g., quantum projection noise and photon shot-noise) on the sensitivity of an idealized atomic magnetometer that utilizes spin squeezing induced by a continuous quantum nondemolition measurement. Such a magnetometer measures spin precession of N atomic spins by detecting optical rotation of far-detuned light. We show that for very short measurement times, the optimal sensitivity scales as N(-3/4); if strongly squeezed probe light is used, the Heisenberg limit of N-1 scaling can be achieved. However, if the measurement time exceeds tau(rel)/N(1/2) in the former case, or tau(rel)/N in the latter, where tau(rel) is the spin relaxation time, the scaling becomes N(-1/2), as for a standard shot-noise-limited magnetometer.
Physical Review A | 2002
A. B. Matsko; Irina Novikova; George R. Welch; Dmitry Budker; D. F. Kimball; S. M. Rochester
When linearly polarized light propagates through a medium in which elliptically polarized light would undergo self-rotation, squeezed vacuum can appear in the orthogonal polarization. A simple relationship between self-rotation and the degree of vacuum squeezing is developed. Taking into account absorption, we find the optimum conditions for squeezing in any medium that can produce self-rotation. We then find analytic expressions for the amount of vacuum squeezing produced by an atomic vapor when light is near-resonant with a transition between various low-angular-momentum states. Finally, we consider a gas of multilevel Rb atoms, and analyze squeezing for light tuned near the D lines under realistic conditions.
Journal of The Optical Society of America B-optical Physics | 2005
Evgeniy B. Alexandrov; M. Auzinsh; Dmitry Budker; D. F. Kimball; S. M. Rochester; Valeriy V. Yashchuk
A brief review is given of topics relating to dynamical processes arising in nonlinear interactions between light and resonant systems (atoms or molecules) in the presence of a magnetic field.
Physical Review A | 2009
Todor Karaulanov; Miriam T. Graf; D. English; S. M. Rochester; Y. J. Rosen; K. Tsigutkin; Dmitry Budker; E. B. Alexandrov; M. V. Balabas; D. F. Jackson Kimball; F. A. Narducci; Szymon Pustelny; Valeriy V. Yashchuk
Atomic-vapor density change due to light induced atomic desorption (LIAD) is studied in paraffincoated rubidium, cesium, sodium and potassium cells. In the present experiment, low-intensity probe light is used to obtain an absorption spectrum and measure the vapor density, while light from an argon-ion laser, array of light emitting diodes, or discharge lamp is used for desorption. Potassium is found to exhibit significantly weaker LIAD from paraffin compared to Rb and Cs, and we were unable to observe LIAD with sodium. A simple LIAD model is applied to describe the observed vapor-density dynamics, and the role of the cell’s stem is explored through the use of cells with lockable stems. Stabilization of Cs vapor density above its equilibrium value over 25 minutes is demonstrated. The results of this work could be used to assess the use of LIAD for vapor-density control in magnetometers, clocks, and gyroscopes utilizing coated cells.