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Physics

Time & frequency

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Displaying 176 - 200 of 272

Generation of Ultrastable microwaves via optical frequency division

June 26, 2011
Author(s)
Tara Fortier, Matthew S. Kirchner, Jennifer A. Taylor, James C. Bergquist, Yanyi Jiang, Andrew Ludlow, Christopher W. Oates, Till P. Rosenband, Scott Diddams, Franklyn Quinlan, Nathan D. Lemke
A frequency-stabilized femtosecond laser optical frequency comb serves as a source of microwave signals having very low close-to-carrier phase noise. Comparison of two independent systems shows combined absolute phase noise of -100 dBc/Hz at an offset of 1

Searching for applications with a fine-toothed comb

April 1, 2011
Author(s)
Nathan R. Newbury
Frequency combs, like many ground-breaking technologies, are simple in concept; they results from the spectrum of any regular train of optical pulses. What is remarkable is that this simple picture can be actually realized in a number of different

The SIM Time Network

March 1, 2011
Author(s)
Michael A. Lombardi, Andrew N. Novick, J. Mauricio Lopez-Romero, Francisco Jimenez, Eduardo de Carlos Lopez, Jean-Simon Boulanger, Raymond Pelletier, Ricardo de Carvalho, Raul Solis, Harold Sanchez, Carlos A. Quevedo, Gregory Pascoe, Daniel Perez, Eduardo Bances, Leonardo Trigo, Victor Masil, Henry Postigo, Anthony Questelles
The Sistema Interamericano de Metrologia (SIM) is a regional metrology organization (RMO) whose members are the national metrology institutes (NMIs) located in the 34 nations of the Organization of American States (OAS). The SIM/OAS region extends

NIST Time and Frequency Bulletin

January 5, 2011
Author(s)
Petrina C. Potts
The Time and Frequency Bulletin provides information on performance of time scales and a variety of broadcasts (and related information) to users of the NIST services.

On-Board GPS Clock Monitoring for Signal Integrity

November 15, 2010
Author(s)
Marc A. Weiss, Pradipta Shome, Ron Beard
Navigation signal integrity is paramount for aviation and safety of life services. Hitherto GPS signal anomaly alerting has been provided primarily by ground based augmentations. Significantly improved navigation signal integrity and quality may be

SIM time scales

October 27, 2010
Author(s)
Michael A. Lombardi, J. Mauricio Lopez-Romero, Nelida Diaz-Munoz
This paper presents an analysis of the performance of some of the time scales generated in the Sistema Interamericano de Metrologia (SIM) region. We emphasize the generation of the first international time scale in near real time, the SIM Time scale (SIMT)

On-Board Signal Integrity for GPS

September 21, 2010
Author(s)
Marc A. Weiss, Pradipta Shome, Ron Beard
The elements of a space-based integrity approach are to monitor the signals on-board the satellite, such that signal performance can be maintained well within desired integrity limits. These elements include 1) a system for monitoring multiple atomic

The Development of a Unified Time and Frequency Program in the SIM Region

September 1, 2010
Author(s)
Michael A. Lombardi, J. Mauricio Lopez-Romero
The Sistema Interamericano de Metrologia (SIM) is one of five major regional metrology organizations (RMOs) recognized by the Bureau International des Poids et Mesures (BIPM). SIM is composed of the national metrology institutes (NMIs) located in the 34

yocto-Newton force detection sensitivity using trapped ions

August 22, 2010
Author(s)
Michael J. Biercuk, Joseph W. Britton, Hermann Uys, Aaron Vandevender, John Bollinger
Recent experimental advances have shown that it is possible to detect forces arising from electric fields at a level of aN/ √Hz (atto = 10 -18 through coupling of micro or nanofabricated mechanical resonators to a variety of physical systems including