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Search Publications

NIST Authors in Bold

Displaying 1026 - 1050 of 2503

Generalized auto-balanced Ramsey spectroscopy of clock transitions

May 23, 2018
Author(s)
V. I. Yudin, A. V. Taichenachev, M. Y. Basalaev, T. Zanon-Willette, Juniper Wren Y. Pollock, Moshe Shuker, Elizabeth Donley, John Kitching
We develop the theory for generalised auto-balanced Ramsey spectroscopy (GABRS), which allows probe-field-induced shifts in atomic clocks to be eliminated. This universal two-loop method, apart from the clock frequency omega, requires the use of an

Revision of the ionization energy of neutral carbon

May 22, 2018
Author(s)
W L. Glab, Haris Kunari, Alexander Kramida
This publication describes a re-analysis of previously published data on neutral carbon (C I) utilizing critically examined and improved values for the line energies of the absorption spectrum of molecular iodine to calibrate the transition energies of C I

Structure and Dynamics of a Graphene Melt

May 22, 2018
Author(s)
Jack F. Douglas, Sinan Keten, Fernando Vargas-Lara, Wenjie Xia
We show by molecular dynamics simulation that bulk materials composed of graphene nanosheets exhibit fluid-like properties similar to linear polymer melts at elevated temperatures and that these materials transform into a glassy or “foam” state at low

A portable cold 87Rb atomic clock with frequency instability at one day in the 10 -15 range

May 21, 2018
Author(s)
Joshua J. Savory, F G. Ascarrunz, L I. Ascarrunz, Alessandro L. Banducci, M C. Delgado Aramburo, Y Dudin, Steven R. Jefferts
We present a small portable cold 87Rubidium atomic clock with frequency uncertainty of less than 𝟑 × 𝟏𝟎 −𝟏𝟓 in one day of averaging time. The clock is under development at SpectraDynamics for the Defense Advanced Research Projects Agency (DARPA) Portable

Effect of Local Oscillator Performance on UWB Based Indoor Localization System

May 21, 2018
Author(s)
Archita Hati, Fabio C. Da Silva, Vladislav P. Gerginov, Craig W. Nelson
We discuss the performance of a commercial Ultra-wideband (UWB) ranging technique for indoor localization. We study the influence of local oscillator's phase noise and its frequency drifts due to temperature variations on the range estimation and ranging

An Integrated-Photonics Optical-Frequency Synthesizer

May 3, 2018
Author(s)
Daryl T. Spencer, Tara E. Drake, Travis Briles, Jordan R. Stone, Laura C. Sinclair, Connor D. Fredrick, Qing Li, Daron A. Westly, Bojan R. Ilic, Aaron Bluestone, Nicolas Volet, Tin Komljenovic, Seung Hoon Lee, Dong Yoon Oh, Myoung-Gyun Suh, Ki Youl Yang, Martin H. Pfeiffer, Tobias J. Kippenberg, Erik Norberg, Kerry Vahala, Kartik A. Srinivasan, Nathan R. Newbury, Luke Theogarajan, John E. Bowers, Scott A. Diddams, Scott B. Papp
Integrated-photonics microchips now enable a range of advanced functionalities for high- coherence applications like data transmission, for highly optimized physical sensors, and for harnessing quantum states, but with size, extensibility, and portability

A Faraday-shielded, DC Stark-free optical lattice clock

May 2, 2018
Author(s)
Kyle P. Beloy, Xiaogang Zhang, William F. McGrew, Nathan M. Hinkley, Tai H. Yoon, Daniele Nicolodi, Robert J. Fasano, Stefan A. Schaeffer, Roger C. Brown, Andrew D. Ludlow
We demonstrate the absence of a DC Stark shift in an ytterbium optical lattice clock. Stray electric fields are suppressed through the introduction of an in-vacuum Faraday shield. Still, the effectiveness of the shielding must be experimentally assessed

An optical clock to go

May 1, 2018
Author(s)
Andrew D. Ludlow
Bringing next-generation atomic clocks out of the lab is not an easy task, but doing so will unlock many new possibilities. As a crucial first step, a portable atomic clock has now been deployed for relativistic geodesy measurements in the Alps.

Progress on Optical-clock-based Time Scale at NIST: Simulations and Preliminary Real-Data Analysis

April 20, 2018
Author(s)
Jian Yao, Jeffrey A. Sherman, Tara M. Fortier, Thomas E. Parker, Judah Levine, Joshua J. Savory, Stefania Romisch, William F. McGrew, Robert J. Fasano, Stefan A. Schaeffer, Kyle P. Beloy, Andrew D. Ludlow
This paper shows the recent NIST work on incorporating an optical clock into a time scale. We simulate a time scale composed of continuously-operating commercial hydrogen masers and an optical frequency standard that does not operate continuously as a

High harmonics with spatially varying ellipticity for spatially-resolved magnetic spectroscopy

April 17, 2018
Author(s)
Daniel D. Hickstein, Jennifer Ellis, Kevin M. Dorney, Nathan J. Brooks, Christian Gentry, Justin M. Shaw, Quynh Nguyen, Christopher A. Mancuso, Henry C. Kapteyn, Margaret M. Murnane, Carlos Hernandez-Garcia
In this work, we present a new method to produce ultrashort pulses of circularly polarized extreme ultraviolet light. We combine two orthogonally-polarized high-harmonic sources to produce a far-field beam with a uniform intensity distribution but with a

Photonic chip for laser stabilization to an atomic vapor at a precision of $10^{-11}$

April 11, 2018
Author(s)
Matthew T. Hummon, Songbai Kang, Douglas G. Bopp, Qing Li, Daron A. Westly, Sangsik Kim, Connor D. Fredrick, Scott A. Diddams, Kartik A. Srinivasan, John E. Kitching
We perform precision spectroscopy of rubidium confined in a micro-machined, 27~mm$^3$ volume, vapor cell using a collimated free space 120~$\bm{\mu}$m diameter laser beam derived directly from a single mode silicon nitride waveguide. With this optical

Mid-infrared frequency comb generation via cascaded quadratic nonlinearities in quasi-phase-matched waveguides

April 5, 2018
Author(s)
Abijith S. Kowligy, Alexander J. Lind, Daniel D. Hickstein, David R. Carlson, Henry R. Timmers, Nima Nader, Flavio Caldas da Cruz, Gabriel G. Ycas
We demonstrate mid-infrared (MIR) frequency comb generation in periodically poled lithium niobate (PPLN) waveguides pumped by nanojoule pulses from a 1.5 um mode-locked Er:fiber laser. The cascaded-c(2) nonlinearity in PPLN yields a nearly octave-spanning

Hyper-Ramsey spectroscopy with probe laser intensity fluctuations

March 29, 2018
Author(s)
Kyle P. Beloy
We examine the influence of probe laser intensity fluctuations on hyper-Ramsey spectroscopy. We assume, as is appropriate for relevant cases of interest, that the probe laser intensity $I$ determines both the Rabi frequency $(\propto\sqrt)$ and the

Incorporating an Optical Clock into a Time Scale at NIST: Simulations and Preliminary Real-Data Analysis

March 29, 2018
Author(s)
Jian Yao, Jeffrey A. Sherman, Tara M. Fortier, Thomas E. Parker, Judah Levine, Joshua J. Savory, Stefania Romisch, William F. McGrew, Robert J. Fasano, Stefan A. Schaeffer, Kyle P. Beloy, Andrew D. Ludlow
This paper shows the recent NIST work on incorporating an optical clock into a time scale. We simulate a time scale composed of continuously-operating commercial hydrogen masers and an optical frequency standard that does not operate continuously as a

SIM Time Scale: 10 years of operation

March 29, 2018
Author(s)
J. M. Lopez, Michael A. Lombardi, E. de Carlos, N. Munoz, C. Ortiz
The Inter-American Metrology System (SIM) is one of the world's five major Regional Metrology Organizations (RMO's). Starting in 2005, the SIM Time and Frequency Metrology Working Group (SIM TFWG) developed a time and frequency comparison network for the

Effects of resonant-laser excitation on the emission properties in a single quantum dot

March 27, 2018
Author(s)
Sergey Polyakov, Vivien Loo, Edward Flagg, Glenn S. Solomon, Olivier Gazzano, Tobias Huber
While many solid-state emitters can be optically excited non-resonantly, resonant excitation is necessary for many quantum information protocols as it often maximizes the non-classicality of the emitted light. Here, we study the resonance fluorescence in a

Topological lattice using multi-frequency radiation

March 19, 2018
Author(s)
Ian B. Spielman, Gediminas Juzeli?nas, Tomas Andrijauskas
We describe a novel technique for creating an artificial magnetic field for ultra-cold atoms using a periodically pulsed pair of counter propagating Raman lasers that drive transitions between a pair of internal atomic spin states: a multi-frequency

Reply to comment on "Relativistic Theory of the Falling Cube Gravimeter"

March 14, 2018
Author(s)
Neil Ashby
The comment\cite{kren17} claims that the paper Relativistic theory of the falling cube gravimeter \cite{ashby17} is incorrect. The authors of this comment assert that optical paths in the two interferometer arms of an absolute gravimeter shift only the
Displaying 1026 - 1050 of 2503
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