U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 2201 - 2225 of 2587

Vibration-induced PM noise in oscillators and its suppression

January 1, 2009
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
High precision oscillators have significant applications in modern communication and navigation systems, radars, and sensors mounted in unmanned aerial vehicles, helicopters, missiles, and other dynamic platforms. These systems must provide their required

Editorial

December 25, 2008
Author(s)
Raymond D. Mountain

Matter-wave self-imaging by atomic center-of-mass motion induced interference

December 18, 2008
Author(s)
Ke Li, Lu Deng, Edward W. Hagley, M.S. Zhan, Marvin G. Payne
We demonstrate matter-wave self-imaging in a stationary light field in the non-Raman-Nath limit. We show that in a non-instantaneous pulsed standing wave grating significant contributions due to the non-negligible atomic center of mass motion and

Development of backlighting sources for Compton radiography diagnostic of Inertial Confinement Fusion targets.

December 8, 2008
Author(s)
Lawrence T. Hudson, A. Tommasini, A MacPhee, D. Hey, T Ma, C. Chen, N Izimi, W Unites, A. MacKinnon, P. Hatchett, B.A. Remington, H.S. Park, P. Springer, J. Koch, O.L. Landen, John F. Seely, G Holland
We present scaled demonstrations of backlighter sources, emitting Bremsstrahlung x rays with photon energies above 75 keV, that we will use to record x-ray Compton radiographic snapshots of cold dense DT fuel in inertial confinement fusion implosions at

A review of time and frequency transfer methods

December 5, 2008
Author(s)
Judah Levine
I will discuss three methods of transmitting time and frequency information: one-way, two-way and common-view. I will describe the advantages and limitations of the different methods including ncertainty estimates for systems that are based on them.

Keeping time in three dimensions

December 1, 2008
Author(s)
Christopher W. Oates
Here I review a paper by Akatsuka et al. that appears in the current volume of Nature Physics. This work describes their latest experimental results on optical lattice clocks, including the first demonstration of a 3-D lattice clock.

Progress on a portable rubidium fountain frequency standard

December 1, 2008
Author(s)
Paul D. Kunz, Thomas P. Heavner, Steven R. Jefferts
We are developing a simple and transportable laser-cooled rubidium (Rb) atomic fountain frequency standard. The optical package for this system uses DFB (distributed feedback) diode lasers and a frequency offset locking scheme to generate the optical

PTTI Capabilities of the Modernized LORAN System

December 1, 2008
Author(s)
Kirk Montgomery, Michael A. Lombardi
This paper covers the current status and future plans of the modernized LORAN systems in North America, the European Union, Asia, & Saudi Arabia. Special focus is placed on the enhanced LORAN system in North America and Europe. These modernized systems

Steering a Time Scale

December 1, 2008
Author(s)
Judah Levine
A time scale is a procedure for combining the data from an ensemble of clocks or frequency standards. The input data to the ensemble algorithm are generally the time (or frequency) differences between each of the members and the reference device for the

The SIM Time and Frequency Network

December 1, 2008
Author(s)
Michael A. Lombardi, Andrew N. Novick, Jose M. Lopez, Francisco Jimenez, Jean-Simon Boulanger, Raymond Pelletier, Ricardo de Carvalho, Raul Solis, Carlos Donado, Harold Sanchez, Carlos A. Quevedo, Gregory Pascoe, Daniel Perez
The Sistema Interamericano de Metrologia (SIM) consists of national metrology institutes (NMIs) located in the 34 member nations of the Organization of American States (OAS), which extends throughout North, Central, and South America, and the Caribbean

Time and Frequency Transfer Activities at NIST

December 1, 2008
Author(s)
Victor S. Zhang, Michael A. Lombardi
The National Institute of Standards and Technology (NIST) maintains one of the world s most accurate and stable time scales, and also developed and maintains the primary frequency standard for the United States. Various techniques are used to compare the

Vibration-induced PM Noise of A Rigid Optical Fiber Spool

December 1, 2008
Author(s)
Jennifer A. Taylor, Craig W. Nelson, Archita Hati, Neil Ashby, David A. Howe
Oscillators operating in field applications are subject to much more strenuous environmental effects than those in the laboratory. These environmental effects, like vibration and temperature fluctuation, have a great impact on the performance of the

Yb Optical Lattice Clock

November 23, 2008
Author(s)
Nathan D. Lemke, Andrew Ludlow, Zeb Barber, N Poli, C.W. Hoyt, Long-Sheng Ma, Jason Stalnaker, Christopher W. Oates, Leo Hollberg, James C. Bergquist, A. Brusch, Tara Fortier, Scott Diddams, Thomas P. Heavner, Steven R. Jefferts, Tom Parker
We describe the development and latest results of an optical lattice clock based on neutral Yb atoms, including investigations based on both even and odd isotopes. We report a fractional frequency uncertainty below 10 -15 for 171Yb.

Josephson phase qubit circuit for the evaluation of advanced tunnel barrier materials

November 21, 2008
Author(s)
Jeffrey S. Kline, Haohua Wang, Seongshik Oh, John M. Martinis, David P. Pappas
We have found that crystalline Josephson junctions have critical current density control problems which decrease circuit yield. We present a qubit circuit designed to accommodate a factor-of-five variation in critical current density for the evaluation of

Cancellation of Vibration-Induced Phase Noise in Optical Fibers

November 15, 2008
Author(s)
Archita Hati, Craig W. Nelson, Jennifer A. Taylor, David A. Howe
Vibration causes mechanical distortions in fiber-optic transmission lines that induce phase fluctuations. A scheme is described which enables electronic cancellation of vibration-induced phase noise in an optical fiber wound on a spool. We report 20 dB or

High resolution 17 keV to 75 keV backlighers for high energy density experiments

November 6, 2008
Author(s)
Lawrence T. Hudson, H.S. Parks, B.R. Maddox, E. Giraldez, P. Hatchett, N. Izumi, M.H. Key, S. LePape, A. MacKinnon, A MacPhee, P.K. Patel, T.W. Phillips, B.A. Remington, John F. Seely, A. Tommasini, R. Town, J. Workman
We have developed 17 keV to 75 keV 1-dimensional and 2-dimensional high-resolution (<10 m) radiography using high-intensity short pulse lasers. High energy K- sources are created by fluorescence from hot electrons interacting in the target material after

A microfabricated photonic magnetometer

October 26, 2008
Author(s)
Jan Preusser, Vladislav Gerginov, Svenja A. Knappe, John E. Kitching
An integrated optically-controlled sensor, suitable for remote, high-sensitivity detection of magnetic fields is presented. The sensor head is free of electrical currents or metal parts, therefore eliminating distortion of the magnetic fields to be

Alpha-Dot or Not: Comparison of Two Single Atom Optical Clocks

October 5, 2008
Author(s)
Till P. Rosenband, David Hume, Chin-Wen Chou, J.C. Koelemeij, A. Brusch, Sarah Bickman, Windell Oskay, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Nathan R. Newbury, William C. Swann, Wayne M. Itano, David J. Wineland, James C. Bergquist
Repeated measurements of the frequency ratio of Hg + and Al + single-atom optical clocks over the course of a year yield a constraint on the possible temporal variation of the fine-structure constant a. The time variation of the measured ratio corresponds

Chip-scale atomic devices: precision atomic instruments based on MEMS

October 5, 2008
Author(s)
John E. Kitching, Svenja A. Knappe, Vladislav Gerginov, Vishal Shah, Peter D. Schwindt, Brad Lindseth, Elizabeth A. Donley, Ying-ju Wang, Eleanor Hodby, Matt Eardley, Ricardo Jimenez Martinez, William C. Griffith, Andrew Geraci, Jan Preusser, Tara C. Liebisch, Hugh Robinson, Leo Hollberg
We describe recent work at NIST to develop compact, low-power instruments based on a combination of precision atomic spectroscopy, advanced diode lasers and microelectromechanical systems (MEMS). Designed to be fabricated in parallel in large numbers

NIST F1 and F2

October 5, 2008
Author(s)
Thomas P. Heavner, Tom Parker, Jon H. Shirley, Steven R. Jefferts
The National Institute of Standards and Technology operates a cesium fountain primary frequency standard, NIST-F1, which has been contributing to International Atomic Time (TAI) since 1999. At the time of the last Symposium on Frequency Standards and

Weight Functions for Biases in Atomic Frequency Standards

October 5, 2008
Author(s)
Jon H. Shirley
We present a unified treatment of frequency-standard biases that vary significantly during the time of measurement. We introduce three time-dependent weight functions built from the solution of the unperturbed equations of motion for a two-level system. By

Recent atomic clock comparisions at NIST

October 1, 2008
Author(s)
Luca Lorini, Neil Ashby, Anders Brusch, Scott Diddams, Robert E. Drullinger, Eric Eason, Tara Fortier, Pat Hastings, Thomas P. Heavner, David Hume, Wayne M. Itano, Steven R. Jefferts, Nathan R. Newbury, Tom Parker, Till P. Rosenband, Jason Stalnaker, William C. Swann, David J. Wineland, James C. Bergquist
The record of atomic clock frequency comparisons at NIST over the past half-decade provides one of the tightest constraints of any present-day, temporal variations of the fundamental constants. Notably, the 6-year record of increasingly precise
Displaying 2201 - 2225 of 2587
Was this page helpful?