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Search Publications

NIST Authors in Bold

Displaying 36601 - 36625 of 74164

High resolution, high collection efficiency in numerical aperture increasing lens microscopy of individual quantum dots

August 9, 2005
Author(s)
Zhiheng H. Liu, B. B. Goldberg, Stephen B. Ippolito, Anthony N. Vamivakas, M. S. Unlu, Richard Mirin
We demonstrate the application of a subsurface solid immersion technique to the photoluminescence spectroscopy of individual quantum dots. Contrasted with the conventional solid immersion microscopy, we used a numerical aperture increasing lens and moved

Chip-Scale Atomic Clocks at NIST

August 7, 2005
Author(s)
John E. Kitching, Svenja A. Knappe, Li-Anne Liew, John Moreland, Hugh Robinson, P Schwindt, V Shah, Vladislav Gerginov, Leo W. Hollberg
We describe recent efforts to develop microfabricated atomic frequency references capable of supporting a wide variety of commercial and military systems such as global positioning and wireless communication. These devices are anticipated to eventually

Uncertainty Budgets for Comparison Calibrations of Thermocouples

August 7, 2005
Author(s)
Dean C. Ripple, K Garrity
By means of concrete examples, we discuss the determination of an uncertainty budget for calibration of thermocouples by comparison techniques. In the first example, the calibration of a type T thermocouple (copper versus copper-nickel alloy) in a stirred

Injection Locking and Phase Control of Spin Transfer Nano-Oscillators

August 5, 2005
Author(s)
William Rippard, Matthew Pufall, Shehzaad F. Kaka, Thomas J. Silva, Stephen E. Russek, Jordan A. Katine
We have directly measured phase locking of spin transfer oscillators to an injected ac current. The oscillators lock to signals up to several hundred megahertz away from their natural oscillation frequencies, depending on the relative strength of the input

Long-Lived Qubit Memory Using Atomic Ions

August 5, 2005
Author(s)
C. Langer, R Ozeri, John D. Jost, J Chiaverini, B. L. DeMarco, A. Ben-Kish, Brad R. Blakestad, Joseph W. Britton, David Hume, Wayne M. Itano, Dietrich G. Leibfried, Rainer Reichle, Till P. Rosenband, Tobias Schaetz, Piet Schmidt, David J. Wineland
We demonstrate experimentally a robust quantum memory using a magnetic-field-independent hyperfine transition in 9Be + atomic ioin qubits at a magnetic field B=0.01194 T. We observe the single physical qubit memory coherence time to be greater than 10

Shaped Pupil Coronagraphs for Planet Finding: Optimization, Manufacturing, and Experimental Results

August 4, 2005
Author(s)
Jeremy Kasdin, Ruslan Belikov, James A. Beall, Robert J. Vanderbei, Michael G. Littman, Michael Carr, Amir Give''on
Current plans call for the first Terrestrial Planet Finder mission, TPF-C, to be a monolithic space telescope with a coronagraph for achieving high contrast. Our group at Princeton pioneered the concept of shaped pupils for high contrast imaging and planet

Spectral Matching With an LED-Based Spectrally Tunable Light Source

August 4, 2005
Author(s)
Irena Fryc, Steven W. Brown, Yoshihiro Ohno
A spectrally tunable light source using a large number of LEDs and an integrating sphere has been designed and constructed at the National Institute of Standards and Technology (NIST). The source is designed to have a capability of producing any visible

Uncertainties in Spherical Near-Field Antenna Measurements

August 3, 2005
Author(s)
Michael H. Francis, Ronald C. Wittmann, Jin-Seob Kang
A general approach is presented for estimating uncertainties in far-field parameters obtained from spherical near-field antenna measurements. The error is approximately bounded in terms of the uncertainty of the probe's receiving pattern and the

Scattering Length Determination From Trapped Pairs of Atoms

August 2, 2005
Author(s)
S Shresta, Eite Tiesinga, E L. Bolda, Carl J. Williams
A method is described for estimating effective scattering lengths via spectroscopy on a trapped pair of atoms. The method relies on the well known phenomena that the energy levels of two atoms in a harmonic trap are shifted by their collisional interaction

4th Annual PKI R&D Workshop "Multiple Paths to Trust" Proceedings

August 1, 2005
Author(s)
Clifford Neuman, William Polk, Nelson Hastings
NIST hosted the fourth annual Public Key Infrastructure (PKI) Research Workshop on April 19-21, 2005. The two and a half day event brought together PKI experts from academia, industry, and government to explore the remaining challenges in deploying public

A Fiber Probe for CMM Measurements of Small Features

August 1, 2005
Author(s)
Jack A. Stone Jr., Balasubramanian Muralikrishnan, John R. Stoup
We report on performance of a new form of fiber probe, which can be used in conjunction with a coordinate measuring machine (CMM) for microfeature measurement. The probe stylus is a glass fiber with a small ball (?75 ?m diameter) glued to the end. When the

Analysis and Evaluation for STEP-Based Electro-Mechanical Assemblies

August 1, 2005
Author(s)
XuanFang Zha, Sebti Foufou, Sudarsan Rachuri, Ram D. Sriram
In this paper, we propose an integrated approach to assemblability analysis and evaluation for STEP-based (STandard for the Exchange of Product model data, officially ISO 10303) electro-mechanical products. First, two assembly representational models are

ATRP in Microchannels

August 1, 2005
Author(s)
Kathryn L. Beers, Tao Wu, Chang Xu
The range of accessible well-defined synthetic polymers expanded dramatically with the discovery of atom transfer radical polymerization (ATRP). In fact, there are so many options for variations of block, statistical and gradient copolymers, not to mention

Calibration and Standardization Issues of UV Sensors for Water Disinfection

August 1, 2005
Author(s)
Thomas C. Larason, Yoshihiro Ohno
Ultraviolet radiation (UV) effectively inactivates common pathogens found in ground and surface waters such as Cryptosporidium, Giardia and most bacterial pathogens. Water treatment facilities recently started using ultraviolet radiation for disinfection

Chemical Warfare Agent Detection Using MEMS Microsensor Arrays

August 1, 2005
Author(s)
Douglas C. Meier, C J. Taylor, Richard E. Cavicchi, Edward White V, M W. Ellzy, K B. Sumpter, Stephen Semancik
Chemical sensors capable of accurate detection of trace quantities of chemical warfare (CW) agents would provide a potent tool for perimeter security, treaty verification, battlefield threat detection, and the protection of civilians in public places

Chemical Warfare Agent Detection Using MEMS-Compatible Microsensor Arrays

August 1, 2005
Author(s)
Douglas C. Meier, C J. Taylor, Richard E. Cavicchi, Edward White, M W. Ellzy, K B. Sumpter, Stephen Semancik
Microsensors have been fabricated consisting of TiO2 and SnO2 sensing films prepared by chemical vapor deposition (CVD) on MEMS- (micro-electromechanical systems) compatible array platforms. Response measurements from these devices to the CW agents GA

Compositional Control in Electrodeposited Co x Pt -x Films.

August 1, 2005
Author(s)
J Mallett, Erik B. Svedberg, S Sayan, Alexander J. Shapiro, L Wielunski, T. E. Madey, P J. Chen, William F. Egelhoff Jr., Thomas P. Moffat
Electrochemical co-deposition of Co(subscript x)Pt(subscript 1-x) alloys is demonstrated at potentials positive to that required to deposit elemental cobalt (underpotential co-deposition). Co-deposition is atributed to the negative enthalpy of Co(subscript
Displaying 36601 - 36625 of 74164
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