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NIST Authors in Bold

Displaying 32076 - 32100 of 73929

A proposed laser frequency comb based wavelength reference for high resolution spectroscopy

September 12, 2007
Author(s)
Steve Osterman, Scott A. Diddams, Matthew Beasley, Cynthia Froning, Leo W. Hollberg, Phillip MacQueen, Vela Mbele, Andrew Weiner
High resolution spectroscopy is the foundation for many of the most challenging and productive of all astronomical observations. A highly precise, repeatable and stable wavelength calibration is especially essential for long term RV observations. The two

Advances in Chip-Scale Atomic Frequency References at NIST

September 12, 2007
Author(s)
Svenja A. Knappe, V Shah, Alan Brannon, Vladislav Gerginov, Hugh Robinson, Z Popovic, Leo W. Hollberg, John E. Kitching
We present new advances in the development of chip-scale atomic frequency references. Coherent population trapping (CPT) resonances usually exhibit contrasts below 10 %, when interrogated with frequency modulated lasers. A relatively simple way to increase

Better Standards, Built Faster

September 12, 2007
Author(s)
Arthur Griesser
Many information transfer standardization efforts focus excessively on minutiae of the transport format (such as XML), to the detriment of the data model. Information standards could be created more expeditiously if the attention lavished on the transport

Biometric Systematic uncertatinty and the User

September 12, 2007
Author(s)
Mary F. Theofanos, Ross J. Micheals, Shahram Orandi, Brian C. Stanton
Often biometric technology and system evaluators are concerned with capturing accurate performance estimates that predict performance for target populations of interest. Occasionally, predictions, and perhaps adjustments, for subpopulations based on

Experimental determination of the inhomogeneous contribution to linewidth in Permalloy films using a time-resolved magneto-optic Kerr effect microprobe

September 12, 2007
Author(s)
Michael Schneider, Thomas Gerrits, Anthony B. Kos, Thomas J. Silva
We adapted a time-resolved magneto-optic microprobe for use with the pulsed inductive microwave magnetometer apparatus, allowing us to measure the magnetization dynamics of a thin Permalloy film at micrometer and millimeter length scales under exactly the

Lattice-based optical clock using an even isotope of Yb

September 12, 2007
Author(s)
Zeb Barber, C Hoyt, Jason Stalnaker, Nathan D. Lemke, Christopher W. Oates, Tara M. Fortier, Scott A. Diddams, Leo W. Hollberg
We describe progress toward an optical lattice clock based on an even isotope of Yb. The 1S_0 - P_0 clock resonance in 174Yb is accessed using a magnetically induced spectroscopic technique. Using ~1 mT static magnetic fields and ~10 uW of probe light

NIST Cesium Fountains - Current Status and Future Prospects

September 12, 2007
Author(s)
Steven R. Jefferts, Thomas P. Heavner, Thomas E. Parker, Jon H. Shirley
We review the current status of the U.S. Primary Frequency Standard, NIST-F1. NIST-F1 is a laser-cooled cesium fountain based frequency standard with an inaccuracy of less than δ f/f {less than or equal to} 5×10 -16 limited mainly by the radiation field in

Optical frequency standards based on mercury and aluminum ions

September 12, 2007
Author(s)
Wayne M. Itano, James C. Bergquist, Anders Brusch, Scott A. Diddams, Tara M. Fortier, Thomas P. Heavner, Leo W. Hollberg, David Hume, Steven R. Jefferts, Luca Lorini, Thomas E. Parker, Till P. Rosenband, Jason Stalnaker
Single-trapped-ion frequency standards based on a 282 nm transition in 199Hg+ and on a 267 nm transition in 27Al+ have been developed at NIST over the past several years. Their frequencies are measured relative to each other and to the NIST primary

Tunable Ionic-Conductivity of Collapsed Sandia Octahedral Molecular Sieves (SOMS)

September 12, 2007
Author(s)
Jason D. Pless, Terry J. Garino, James E. Maslar, Tina M. Nenoff
The structure-property relationship between atomic cation substitution and bulk scale conductivity in perovskites has been studied systematically. A series of Na-Nb perovskites has been synthesized via two methods (1) ion-exchange or (2) synthetic metal

Covalent Attachment of Photoluminescent Silicon Nanoparticles to Streptavidin

September 11, 2007
Author(s)
Jonghoon Choi, Peter Niarhos, Nam S. Wang, Vytas Reipa
We have covalently attached multiple fluorescent silicon nanocrystals (SNs) to streptavidin molecule. Selective conjugation of SNs to a target protein is accomplished using sequential silicon surface termination chemistry. In the first step, freshly

An Optical Fiber-Based Source of Polarization-Entangled Photon Pairs

September 10, 2007
Author(s)
Jingyun Fan, M D. Eisaman, Alan L. Migdall
We describe an achromatic, phase-stable, broadband source of polarization-entangled photon pairs with high spectral brightness that uses four-wave mixing in a fiber Sagnac interferometer. We achieved a polarization-entangled two-photon coincidence rate of

Detector Dead-Time Effects and Paralyzability in High-Speed Quantum Key Distribution

September 10, 2007
Author(s)
Daniel Rogers, Joshua C. Bienfang, Anastase Nakassis, Hai Xu, Charles W. Clark
Recent advances in quantum key distribution (QKD) have given rise to systems that operate at transmission periods significantly shorter than the dead times of their component single-photon detectors. As systems continue to increase in transmission rate

Instrumentation, Metrology, and Standards for Nanomanufacturing

September 10, 2007
Author(s)
Michael T. Postek, Andras Vladar, John A. Kramar, L A. Stern, John Notte, Sean McVey
Helium Ion Microscopy (HIM) is a new, potentially disruptive technology for nanotechnology and nanomanufacturing. This methodology presents a potentially revolutionary approach to imaging and measurements which has several potential advantages over the

Acoustic Thermometry Results From 271 K to 552 K

September 8, 2007
Author(s)
Dean C. Ripple, Gregory F. Strouse, Michael R. Moldover
The NIST Acoustic Thermometer determines the thermodynamic temperature from measurements of ratios of the speed of sound of argon in a spherical cavity. We report recent results for T - T90 on 12 isotherms spanning the range 271 K to 552 K. (T is the

A New Taxonomy for Analyzing Smart Card-based Authentication Processes

September 7, 2007
Author(s)
Ramaswamy Chandramouli
As part of E-Government and security initiatives, smart cards are now being increasingly deployed as authentication tokens. The existing classification of authentication factors into What you Know, What You Have and What You Are- does not provide a good

Infrastructure Standards for Smart ID-Cards Deployment

September 7, 2007
Author(s)
Ramaswamy Chandramouli, Philip Lee
Smart cards are being increasingly deployed for many applications. Typical applications are Subscriber Identification Module (SIM) cards (in Telecommunication), Micropayment (in Financial Transactions), Commuter Cards (in Urban Transportation Systems) and

STANDARDS DEVELOPMENT FOR REMOTE SENSING AT MICROWAVE AND TERAHERTZ FREQUENCIES

September 7, 2007
Author(s)
James P. Randa, Eyal Gerecht, Dave K. Walker, Amanda Cox, Dazhen Gu, Lixing You, Robert L. Billinger
The Noise Project in the Electromagnetics Division of the National Institute of Standards and Technology (NIST) has proposed the development of standards for microwave brightness temperature, for use in remote-sensing applications such as satellite-based

The third industrial fluid properties simulation challenge

September 7, 2007
Author(s)
F Case, John K. Brennan, Anne M. Chaka, Kerwin Dobbs, Daniel G. Friend, David Frurip, Peter A. Gordon, J Moore, Raymond D. Mountain, J Olson, Richard B. Ross, Martin Schiller, Vincent K. Shen
The third Industrial fluid properties simulation challenge was held from March to September 2006. As in the previous two events, contestants were challenged to predict specific, industrially relevant, properties of fluid systems. Their efforts were judged

A New Approach to Ventilation Measurements in Enclosure Fires

September 5, 2007
Author(s)
Rodney A. Bryant
The application of Stereoscopic Particle Image Velocimetry (SPIV) is a new approach to quantifying the ventilation in enclosure fires. SPIV is a non-intrusive optical measurement technique which measures the displacement of tracer particles in a flow. The
Displaying 32076 - 32100 of 73929
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