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Yuqin Zong, Steven W. Brown, Bettye C. Johnson, Keith R. Lykke, Yoshihiro Ohno
In many applications, the measurement accuracy of spectroradiometers, particularly instruments with a single dispersive element, is limited by the presence of stray radiation within the instrument. A simple, practical method has been developed to correct a
Energy levels, with classifications and uncertainties, have been compiled for the spectra of the neutral atom and all positive ions of rubidium (Z=37). Wavelengths with classifications, intensities, and transition probabilities are also tabulated. In
A magazine article that looks at the history of time signal stations, beginning with the first radio experiments in the 1890's and continuing to the present day. It discusses both shortwave time signal stations, best known for their voice announcements of
Kristine A. Bertness, Alexana Roshko, Norman A. Sanford, Joy Barker, Albert Davydov
We have identified crystal growth conditions in gas-source molecular beam epitaxy (MBE) that lead to spontaneous formation of GaN nanowires with high aspect ratio on Si (1 1 1) substrates. The nanowires were oriented along the GaN c-axis and normal to the
We propose a new ion trap, the rotating-rf trap, in which motion of a charged particle is described not by Mathieu-type functions but by trigonometric functions. In the rotating-rf trap, a quadrupole electric field confines charged particles, whereas in a
J Chiaverini, Brad R. Blakestad, Joseph W. Britton, John D. Jost, C. Langer, Dietrich G. Leibfried, R Ozeri, David J. Wineland
We investigate a surface-mounted electrode geometry for miniature linear radio frequency Paul ion traps. The electrodes reside in a single plane on a substrate, and the pseudopotential minimum of the trap is located above the substrate at a distance on
Standard Reference Material (SRM) 2519a is an optical-fiber-coupled wavelength reference based on the fundamental absorption lines of hydrogen cyanide H 13C 14N in the 1530 nm to 1565 nm region. The main difference between SRM 2519a and its predecessor
With high thermal conductivity and resistance to damage, carbon nanotube coatings are a promising new technology for thermal detectors. NIST and NREL scientists are exploring this viable alternative with the aim of developing better radiometric standards
A series of interaction models for ethylene oxide are developed for use in molecular simulation of the thermal properties of both the gas and liquid phases. While it is possible to develop nonpolarizable models to accurately generate either the gas or
We are exploring air wavelength references useful for interferometry. Femtosecond comb frequency measurements determine mode wavelengths of a stable optical cavity in vacuum, and subsequently a tunable laser is locked to the modes in air.
Alan Brannon, J Breitbarth, Z Popovic, Vladislav Gerginov, V Shah, Svenja A. Knappe, Leo W. Hollberg, John E. Kitching
We report the first local oscillator (LO) demonstrating viability in terms of performance, size, and power, for chip scale atomic clocks (CSAC) at the National Institute of Standards and Technology in Boulder, CO. This volgate-controlled oscillator (VCO)
John J. McFerran, Eugene N. Ivanov, A Bartels, G Wilpers, Christopher W. Oates, Scott A. Diddams, Leo W. Hollberg
We demonstrate the low noise synthesis of a harmonic comb of microwave frequencies using a femtosecond laser based synthesiser that is referenced to a cabity-stabilised laser. The residual phase noise is ~ -110dBc/Hz at 1 Hz from the 10 GHz harmonic. An
J Chiaverini, Joseph W. Britton, Dietrich G. Leibfried, Emanuel H. Knill, Murray D. Barrett, Brad R. Blakestad, Wayne M. Itano, John D. Jost, C. Langer, R Ozeri, Tobias Schaetz, David J. Wineland
One of the most interesting future applications of quantum computers is Shor's factoring algorithm, which provides an exponential speedup compared to known classical algorithms. The crucial final step in Shor's algorithm is the quantum Fourier transform
Leo W. Hollberg, Christopher W. Oates, G Wilpers, C Hoyt, Zeb Barber, Scott A. Diddams, W Oskay, James C. Bergquist
Ideas for using visible light from atomic transitions for precision instrumentation and metrology go back at least to the 1800's. There are several good reasons to use optical frequencies, and with the scientific and technological advances of the last
Long-Sheng Ma, Zhiyi Bi, A Bartels, Lennart Robertsson, Massimo Zucco, Robert Windeler, G Wilpers, Christopher W. Oates, Leo W. Hollberg, Scott A. Diddams
Two types of international comparisons of femtosecond laser frequency combs have been performed in France and the USA. Five combs were involved in the comparisons. Three combs, of which two are transportable, employ nonlinear photonic crystal fiber (PCF)
A Bartels, Scott Diddams, Christopher W. Oates, G Wilpers, James C. Bergquist, Windell Oskay, Leo W. Hollberg
Using femtosecond laser frequency combs to convert optical frequency references to the microwave domain, we demonstrate the synthesis of 10 GHz signals having an instability of
This article described recent research in the Time and Frequency Division at NIST to develop highly miniaturized atomic frequency references using microfabrication technologies. We discuss the overall physics package design, fabrication of individual
This book chapter reviews absolute radiometers, mainly of two types. The first type, briefly treated, are predictable quantum efficiency detectors such as self-calibrated silicon photodiodes. The second type, treated in much more detail, are absolute