Academic Appointments


2018-19 Courses


Stanford Advisees


All Publications


  • Matter wave lensing to picokelvin temperatures. Physical review letters Kovachy, T., Hogan, J. M., Sugarbaker, A., Dickerson, S. M., Donnelly, C. A., Overstreet, C., Kasevich, M. A. 2015; 114 (14): 143004-?

    Abstract

    Using a matter wave lens and a long time of flight, we cool an ensemble of ^{87}Rb atoms in two dimensions to an effective temperature of less than 50_{-30}^{+50}  pK. A short pulse of red-detuned light generates an optical dipole force that collimates the ensemble. We also report a three-dimensional magnetic lens that substantially reduces the chemical potential of evaporatively cooled ensembles with a high atom number. By observing such low temperatures, we set limits on proposed modifications to quantum mechanics in the macroscopic regime. These cooling techniques yield bright, collimated sources for precision atom interferometry.

    View details for PubMedID 25910118

  • Enhanced Atom Interferometer Readout through the Application of Phase Shear PHYSICAL REVIEW LETTERS Sugarbaker, A., Dickerson, S. M., Hogan, J. M., Johnson, D. M., Kasevich, M. A. 2013; 111 (11)

    Abstract

    We present a method for determining the phase and contrast of a single shot of an atom interferometer. The application of a phase shear across the atom ensemble yields a spatially varying fringe pattern at each output port, which can be imaged directly. This method is broadly relevant to atom-interferometric precision measurement, as we demonstrate in a 10 m ^{87}Rb atomic fountain by implementing an atom-interferometric gyrocompass with 10 mdeg precision.

    View details for DOI 10.1103/PhysRevLett.111.113002

    View details for Web of Science ID 000324233400007

    View details for PubMedID 24074082

  • Multiaxis inertial sensing with long-time point source atom interferometry. Physical review letters Dickerson, S. M., Hogan, J. M., Sugarbaker, A., Johnson, D. M., Kasevich, M. A. 2013; 111 (8): 083001-?

    Abstract

    We show that light-pulse atom interferometry with atomic point sources and spatially resolved detection enables multiaxis (two rotation, one acceleration) precision inertial sensing at long interrogation times. Using this method, we demonstrate a light-pulse atom interferometer for ^{87}Rb with 1.4 cm peak wave packet separation and a duration of 2T=2.3  s. The inferred acceleration sensitivity of each shot is 6.7×10^{-12}g, which improves on previous limits by more than 2 orders of magnitude. We also measure Earth's rotation rate with a precision of 200  nrad/s.

    View details for PubMedID 24010433

  • New method for gravitational wave detection with atomic sensors. Physical review letters Graham, P. W., Hogan, J. M., Kasevich, M. A., Rajendran, S. 2013; 110 (17): 171102-?

    Abstract

    Laser frequency noise is a dominant noise background for the detection of gravitational waves using long-baseline optical interferometry. Amelioration of this noise requires near simultaneous strain measurements on more than one interferometer baseline, necessitating, for example, more than two satellites for a space-based detector or two interferometer arms for a ground-based detector. We describe a new detection strategy based on recent advances in optical atomic clocks and atom interferometry which can operate at long baselines and which is immune to laser frequency noise. Laser frequency noise is suppressed because the signal arises strictly from the light propagation time between two ensembles of atoms. This new class of sensor allows sensitive gravitational wave detection with only a single baseline. This approach also has practical applications in, for example, the development of ultrasensitive gravimeters and gravity gradiometers.

    View details for PubMedID 23679702

  • Generation of 43 W of quasi-continuous 780 nm laser light via high-efficiency, single-pass frequency doubling in periodically poled lithium niobate crystals OPTICS LETTERS Chiow, S., Kovachy, T., Hogan, J. M., Kasevich, M. A. 2012; 37 (18): 3861-3863

    Abstract

    We demonstrate high-efficiency frequency doubling of the combined output of two 1560 nm 30 W fiber amplifiers via single pass through periodically poled lithium niobate (PPLN) crystals. The temporal profile of the 780 nm output is controlled by adjusting the relative phase between the seeds of the amplifiers. We obtain a peak power of 34 W of 780 nm light by passing the combined output through one PPLN crystal, and a peak power of 43 W by passing through two cascading PPLN crystals. This source provides high optical power, excellent beam quality and spectral purity, and agile frequency and amplitude control in a simple and compact setup, which is ideal for applications such as atom optics using Rb atoms.

    View details for Web of Science ID 000309046300041

    View details for PubMedID 23041884

  • A high-performance magnetic shield with large length-to-diameter ratio REVIEW OF SCIENTIFIC INSTRUMENTS Dickerson, S., Hogan, J. M., Johnson, D. M., Kovachy, T., Sugarbaker, A., Chiow, S., Kasevich, M. A. 2012; 83 (6)

    Abstract

    We have demonstrated a 100-fold improvement in the magnetic field uniformity on the axis of a large aspect ratio, cylindrical, mumetal magnetic shield by reducing discontinuities in the material of the shield through the welding and re-annealing of a segmented shield. The three-layer shield reduces Earth's magnetic field along an 8 m region to 420 μG (rms) in the axial direction, and 460 and 730 μG (rms) in the two transverse directions. Each cylindrical shield is a continuous welded tube which has been annealed after manufacture and degaussed in the apparatus. We present both experiments and finite element analysis that show the importance of uniform shield material for large aspect ratio shields, favoring a welded design over a segmented design. In addition, we present finite element results demonstrating the smoothing of spatial variations in the applied magnetic field by cylindrical magnetic shields. Such homogenization is a potentially useful feature for precision atom interferometric measurements.

    View details for DOI 10.1063/1.4720943

    View details for Web of Science ID 000305833100056

    View details for PubMedID 22755663

  • Reply to "Comment on 'Atomic gravitational wave interferometric sensor'" PHYSICAL REVIEW D Dimopoulos, S., Graham, P. W., Hogan, J. M., Kasevich, M. A., Rajendran, S. 2011; 84 (2)
  • An atomic gravitational wave interferometric sensor in low earth orbit (AGIS-LEO) GENERAL RELATIVITY AND GRAVITATION Hogan, J. M., Johnson, D. M., Dickerson, S., Kovachy, T., Sugarbaker, A., Chiow, S., Graham, P. W., Kasevich, M. A., Saif, B., Rajendran, S., Bouyer, P., Seery, B. D., Feinberg, L., Keski-Kuha, R. 2011; 43 (7): 1953-2009
  • Precision angle sensor using an optical lever inside a Sagnac interferometer OPTICS LETTERS Hogan, J. M., Hammer, J., Chiow, S., Dickerson, S., Johnson, D. M., Kovachy, T., Sugarbaker, A., Kasevich, M. A. 2011; 36 (9): 1698-1700

    Abstract

    We built an ultra-low-noise angle sensor by combining a folded optical lever and a Sagnac interferometer. The instrument has a measured noise floor of 1.3 prad/√Hz at 2.4 kHz. We achieve this record angle sensitivity using a proof-of-concept apparatus with a conservative N=11 bounces in the optical lever. This technique could be extended to reach subpicoradian/√Hz sensitivities with an optimized design.

    View details for Web of Science ID 000290037300058

    View details for PubMedID 21540973

  • Picosecond Optical Switching Using RF Nonlinear Transmission Lines JOURNAL OF LIGHTWAVE TECHNOLOGY Johnson, D. M., Hogan, J. M., Chiow, S., Kasevich, M. A. 2011; 29 (5): 666-669
  • Optical lattices as waveguides and beam splitters for atom interferometry: An analytical treatment and proposal of applications PHYSICAL REVIEW A Kovachy, T., Hogan, J. M., Johnson, D. M., Kasevich, M. A. 2010; 82 (1)
  • Broadband optical serrodyne frequency shifting OPTICS LETTERS Johnson, D. M., Hogan, J. M., Chiow, S., Kasevich, M. A. 2010; 35 (5): 745-747

    Abstract

    We demonstrate serrodyne frequency shifting of light from 200 MHz to 1.2 GHz with an efficiency of better than 60%. The frequency shift is imparted by an electro-optic phase modulator driven by a high-frequency high-fidelity sawtooth waveform that is passively generated by a commercially available nonlinear transmission line. We also implement a push-pull configuration using two serrodyne-driven phase modulators, allowing for continuous tuning between -1.6 GHz and +1.6 GHz. Compared with competing technologies, this technique is simple and robust, and it offers the largest available tuning range in this frequency band.

    View details for Web of Science ID 000275826700044

    View details for PubMedID 20195339

  • Gravitational wave detection with atom interferometry PHYSICS LETTERS B Dimopoulos, S., Graham, P. W., Hogan, J. M., Kasevich, M. A., Rajendran, S. 2009; 678 (1): 37-40
  • Atomic gravitational wave interferometric sensor PHYSICAL REVIEW D Dimopoulos, S., Graham, P. W., Hogan, J. M., Kasevich, M. A., Rajendran, S. 2008; 78 (12)
  • General relativistic effects in atom interferometry PHYSICAL REVIEW D Dimopoulos, S., Graham, P. W., Hogan, J. M., Kasevich, M. A. 2008; 78 (4)
  • How to test atom and neutron neutrality with atom interferometry PHYSICAL REVIEW LETTERS Arvanitaki, A., Dimopoulos, S., Geraci, A. A., Hogan, J., Kasevich, M. 2008; 100 (12)

    Abstract

    We propose an atom-interferometry experiment based on the scalar Aharonov-Bohm effect which detects an atom charge at the 10{-28}e level, and improves the current laboratory limits by 8 orders of magnitude. This setup independently probes neutron charges down to 10{-28}e, 7 orders of magnitude below current bounds.

    View details for DOI 10.1103/PhysRevLett.100.120407

    View details for Web of Science ID 000254473800007

    View details for PubMedID 18517846

  • Testing general relativity with atom interferometry PHYSICAL REVIEW LETTERS Dimopoulos, S., Graham, P. W., Hogan, J. M., Kasevich, M. A. 2007; 98 (11)

    Abstract

    The unprecedented precision of atom interferometry will soon lead to laboratory tests of general relativity to levels that will rival or exceed those reached by astrophysical observations. We propose such an experiment that will initially test the equivalence principle to 1 part in 10(15) (300 times better than the current limit), and 1 part in 10(17) in the future. It will also probe general relativistic effects - such as the nonlinear three-graviton coupling, the gravity of an atom's kinetic energy, and the falling of light - to several decimals. In contrast with astrophysical observations, laboratory tests can isolate these effects via their different functional dependence on experimental variables.

    View details for DOI 10.1103/PhysRevLett.98.111102

    View details for Web of Science ID 000244959300014

    View details for PubMedID 17501039