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 1901 - 1925 of 2587

An 84 Pixel All-Silicon Corrugated Feedhorn for CMB Measurements

December 8, 2011
Author(s)
John P. Nibarger, James A. Beall, Daniel T. Becker, Joseph W. Britton, Hsiao-Mei Cho, Anna E. Fox, Gene C. Hilton, Johannes Hubmayr, Dale Li, Kent D. Irwin, Jeffrey L. Van Lanen, Jeff McMahon, Ki Won Yoon
Silicon platelet corrugated feedhorn for cosmic microwave background (CMB) measurements in the mm wave (130 to 170 GHz) have been developed for deployment for the polarization sensitive upgrade to both the Atacama Cosmology Telescope (ACTpol) and the South

Noise floor reduction of an Er:fiber laser-based photonic microwave generator

December 1, 2011
Author(s)
Haifeng (. Jiang, Jennifer A. Taylor, Franklyn J. Quinlan, Tara M. Fortier, Scott A. Diddams
Commercially available erbium-doped mode-locked fiber lasers are compact, robust, and suitable to be the frequency divider of an ultra-low phase noise photonic microwave generator. However, for a mode-locked fiber laser with repetition rate of a few

The New SI: The Role of CODATA

December 1, 2011
Author(s)
David B. Newell, Peter J. Mohr, Barry N. Taylor
The mission of the International Council for Science : Committee on Data for Science and Technology (CODATA ) is to strengthen international science for the benefit of society by promoting improved scientific and technical data management and use. One of

Cold-collision-shift cancelation and inelastic scattering in a Yb optical lattice clock

November 28, 2011
Author(s)
Andrew D. Ludlow, Nathan D. Lemke, Jeffrey A. Sherman, Christopher W. Oates, G. Quemener, J. von Stecher, A.M. Rey
Recently, ρ-wave cold collisions were shown to dominate the density-dependent shift of the clock transition frequency in a 171Yb optical lattice clock. Here we demonstrate that by operating such a system at the proper excitation fraction, the cold

Quantum simulation of the hexagonal Kitaev model with trapped ions

November 25, 2011
Author(s)
Dietrich G. Leibfried, Roman Schmied , Janus H. Wesenberg
We present a detailed study of quantum simulations of coupled spin systems in surface-electrode ion-trap arrays, and illustrate our findings with a proposed implementation of the hexagonal Kitaev model [A. Kitaev, Annals of Physics 321,2 (2006)]. The e

High-resolution single-mode fiber-optic distributed Raman sensor for absolute temperature measurement using superconducting nanowire single-photon detectors

November 17, 2011
Author(s)
Michael G. Tanner, Shellee D. Dyer, Burm Baek, Robert Hadfield, Sae Woo Nam
We demonstrate a distributed fiber Raman sensor for absolute temperature measurement with spatial resolution on the order of 1 cm at 1550 nm wavelength in single mode fiber using superconducting nanowire single photon detectors. Rapid measurements are

Generation and characterization of high-purity, pulsed squeezed light at telecom wavelengths from pp-KTP

November 15, 2011
Author(s)
Thomas Gerrits, Martin J. Stevens, Burm Baek, Brice R. Calkins, Adriana E. Lita, Scott C. Glancy, Emanuel H. Knill, Sae Woo Nam, Richard P. Mirin, Robert Hadfield, Ryan Bennink, Warren Grice, Sander N. Dorenbos, Tony Zijlstra, Teun Klapwijk, Val Zwiller
We characterize a pp-KTP crystal designed to produce pure single mode squeezed vacuum at 1570 nm. Measurements show a raw (corrected) Hong-Ou-Mandel interference with 86 % (90 %) visibility and a circular joint spectral probability distribution with a

Characterizing Dynamic Effects of Oscillator Power Cycling

November 14, 2011
Author(s)
David A. Howe, Danielle G. Lirette, Neil Ashby, Archita Hati, Craig W. Nelson
We create a measurement technique and metrics consistent with easy interpretation to be used in development of new oscillators specifically for applications in which the oscillator’s power is turned on and off. This is useful in predicting the performance

Improvements to A Transportable Atomic Fountain Laser system

November 14, 2011
Author(s)
Paul D. Kunz, Vladislav Gerginov, Thomas P. Heavner, Steven R. Jefferts
We are developing a transportable rubidium (Rb) atomic fountain frequency standard which uses independently phase-locked diode lasers for laser-cooling. At this point in time, we have not demonstrated sub-Doppler (υKelvin) atom temperatures using out

New Improved System for WWVB Broadcast

November 14, 2011
Author(s)
John P. Lowe, Matthew J. Deutch, Glenn K. Nelson, Douglas D. Sutton, William C. Yates, Peder Hansen, Oren Eliezer, Tom Jung, Stephen Morrison, Yingsi Liang, Dinesh Rajan, Sidharth Balasubramanian, Arun Ramasami, Waleed Khalil
The WWVB broadcast of the time-code signal has not undergone major changes in its communications protocol and modulation scheme since its introduction in 1963. Its amplitude-modulation (AM) and pulse-width based representations of its digital symbols were

Synchronizing Computer Clocks by the Use of Kalman Filters

November 14, 2011
Author(s)
Judah Levine
The National Institute of Standards and Technology (NIST) currently operates 35 public network time servers that are located at many different sites in the United States. The servers provide time messages over the public Internet in a number of different

Common-Arm Counter-Propagating Interferometer for Fiber Vibration Measurements

November 1, 2011
Author(s)
Craig W. Nelson, Archita Hati, David A. Howe
We propose and demonstrate a novel technique to measure the vibration sensitivity of two-port fiber-based optical components. It uses a common-arm counter-propagating frequency-shifted interferometer that cancels the vibration induced phase noise of the

A 750 mW, continuous-wave, solid-state laser source at 313 nm for cooling and manipulating trapped 9Be+ ions

October 28, 2011
Author(s)
Andrew C. Wilson, Christian Ospelkaus, Aaron Vandevender, J. A. Mlynek, Kenton R. Brown, Dietrich G. Leibfried, David J. Wineland
We present a solid-state laser system that generates 750 mW of continuous-wave, single frequency, output at 313 nm. Sum-frequency generation with fiber lasers at 1550 nm and 1051 nm produces up to 2 W at 626 nm. This visible light is then converted to UV

Porous Superhydrophobic Membranes: Hydrodynamic Anomaly in Oscillating Flows

October 17, 2011
Author(s)
Sukumar Rajauria, O. Ozsun, John R. Lawall, V. Yakhot, Kamil L. Ekinci
Inspiration for man-made superhydrophobic surfaces comes from Nature: the Lotus leaf [1–3], for instance, exploits superhydrophobicity to keep its surface dry and clean from contaminants. Superhydrophobicity emerges due to roughness on a chemically

Mid-infrared upconversion spectroscopy based on a Yb:fiber frequency laser

October 11, 2011
Author(s)
Scott A. Diddams, Todd Johnson
We present a system for molecular spectroscopy using a mid-infrared broadband frequency comb source with near infrared detection. Difference frequency generation of a Yb:fiber frequency comb produced a mid-infrared (MIR) comb tunable from 2.7 − 4.7 υm

Carbon nanotube arrays for absolute IR and THz radiometry

October 2, 2011
Author(s)
John H. Lehman, Kerry N. Betz, Erich N. Grossman
We have assembled and evaluated a novel electrically calibrated thermopile having an array of 1.5 mm long multiwalled carbon nanotubes as the radiation absorber. We find very low reflectance at the 390 υm laser wavelength and excellent agreement between

The Evolution of Time Measurement, Part 2 - Quartz Clocks

September 30, 2011
Author(s)
Michael Lombardi
A historical article about the origins and the development of quartz clocks and oscillators (Part II of a IV-part series). It describes the discovery of piezoelectricity, the development of the first quartz oscillators, how quartz oscillators were

SEM Induced Shrinking of Solid State Nanopores for Single Molecule Detection

September 22, 2011
Author(s)
Anmiv Prahbu, Kevin J. Freedman, Joseph W. Robertson, Zhorro Nikolov, John J. Kasianowicz, MinJun Kim
We have investigated the shrinkage of solid state nanopores by a scanning electron microscope and find the process to be reproducible and dependant beam parameters such as the accelerating voltage and electron flux. The shrinking phenomenon does not

A Laser-Cooled Frequency Standard for GPS

September 20, 2011
Author(s)
Thomas P. Heavner, Stephan E. Barlow, Marc A. Weiss, Neil Ashby, Steven R. Jefferts
NIST is in an initial phase of developing a prototype laser-cooled atomic frequency standard (AFS) for potential use in a future GPS system. The expected fractional frequency stability or Allan deviation, ς y(τ), will be 2x10 -13 at one second, improving
Displaying 1901 - 1925 of 2587
Was this page helpful?