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Search Publications by: Scott Diddams (Assoc)

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Displaying 151 - 175 of 320

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

Frequency Comparison of Al + and Hg + Optical Standards

June 24, 2007
Author(s)
Till P. Rosenband, David Hume, Anders Brusch, Luca Lorini, P. O. Schmidt, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Nathan R. Newbury, W Swann, Windell Oskay, Wayne M. Itano, David J. Wineland, James C. Bergquist
We compare the frequencies of two single ion frequency standards: 27Al + and 199Hg +. Systematic fractional frequency uncertainties of both standards are below 10 -16, and the statistical measurement uncertainty is below 5 x 10 -17. Recent ratio

Observation of the 1 S 0 - 3 P 0 clock transition in 27 Al +

June 1, 2007
Author(s)
Till P. Rosenband, P. O. Schmidt, David Hume, Wayne M. Itano, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Jeroen Koelemeij, James C. Bergquist, David J. Wineland
We report for the first time, laser spectroscopy of the 1S 0 – 3P 0 clock transition in 27Al +. A single aluminum ion and a single beryllium ion are simultaneously confined in a linear Paul trap, coupled by their mutual Coulomb repulsion. This coupling

Improved Limits on Variation of the Fine Structure Constant and Violation of Local Position Invariance

May 29, 2007
Author(s)
Tara M. Fortier, Neil Ashby, James C. Bergquist, Marie Delaney, Scott A. Diddams, Thomas P. Heavner, Leo W. Hollberg, Wayne M. Itano, Steven R. Jefferts, K Kim, Windell Oskay, Thomas E. Parker, Jon H. Shirley, Jason Stalnaker, Filippo Levi, Luca Lorini
We report tests of Local Position Invariance (LPI) and constancy of fundamental constants from measurements of the frequency ratio of the 282-nm 199Hg + optical clock transition to the ground-state hyperfine splitting in 133Cs. Analysis of the frequency

Stable Laser System for Probing the Clock Transition at 578 nm in Neutral Ytterbium

May 29, 2007
Author(s)
Christopher W. Oates, Zeb Barber, Jason Stalnaker, C Hoyt, Tara M. Fortier, Scott A. Diddams, Leo W. Hollberg
In this paper we describe a new laser system we have developed to probe the ultra-narrow 1S 0 -> 3P 0 clock transition at 578 nm in neutral ytterbium. The yellow light is produced by sum frequency generation in a periodically-poled waveguide. With

Fiber laser-based frequency combs with high relative frequency stability

May 28, 2007
Author(s)
Nathan R. Newbury, William C. Swann, Ian R. Coddington, J. C. Bergquist, Scott Diddams, Luca Lorini
We describe our current low-noise fiber-laser frequency comb and present measurements of its residual instability. Through a comparison with a Ti:Sapphire frequency comb, we measure residual fractional frequency instabilities (Allan deviation) of 6x10 -17

Multi-octave optical coherence spanning hundreds of meters

May 6, 2007
Author(s)
Ian R. Coddington, Luca Lorini, William C. Swann, J. C. Bergquist, Y. Le Coq, C. W. Oates, Qudsia Quraishi, Jason Stalnaker, Scott Diddams, Nathan R. Newbury
We demonstrate coherent transfer of optical signals with radian level noise (in a 3.5 MHz bandwidth) through a series of laser systems spanning from 657 nm to 1535 nm and several hundred meter distances.

Residual stability of a fiber-based frequency comb

May 6, 2007
Author(s)
William C. Swann, Ian R. Coddington, Luca Lorini, Jason Stalnaker, J. C. Bergquist, Scott Diddams, Nathan R. Newbury
Abstract: We present measurements of the residual frequency stability across a fiber frequency comb by comparison through a Ti:sapphire frequency comb. We find 6 x 10 -17 stability at one second and 1 x 10 -18 at 1000 seconds.

Coherent optical link over hundreds of metres and hundreds of terahertz with subfemtosecond timing jitter

May 1, 2007
Author(s)
Ian R. Coddington, William C. Swann, Luca Lorini, J. C. Bergquist, K Feder, Y. Le Coq, Jeffrey W. Nicholson, C. W. Oates, Qudsia Quraishi, Paul S. Westbrook, Scott Diddams, Nathan R. Newbury
Recent developments in stabilized lasers have resulted in ultrastable optical oscillators with spectral purities below 1 Hz refs 1-6. These oscillators are not transportable at present and operate at a single frequency. To realize their full potential, a

Absolute frequency measurement of the neutral 40 Ca optical frequency standard at 657 nm based on microkelvin atoms

March 14, 2007
Author(s)
G Wilpers, Christopher W. Oates, Scott A. Diddams, A Bartels, Tara M. Fortier, Windell Oskay, James C. Bergquist, Steven R. Jefferts, Thomas P. Heavner, Thomas E. Parker, Leo W. Hollberg
We report an absolute frequency measurement of the optical clock transition at 657 nm in 40Ca with a relative uncertainty of 7.5x10 -15, the most accurate frequency measurement of a neutral atom optical transition to date. Relative instabilities of 2x10

Precision Atomic Spectroscopy for Improved Limits on Variation of the Fine Structure Constant and Local Position Invariance

February 16, 2007
Author(s)
Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Neil Ashby, Luca Lorini, Windell Oskay, Marie Delaney, James C. Bergquist, Steven R. Jefferts, Thomas E. Parker, Thomas P. Heavner, Filippo Levi, Jon H. Shirley, Wayne M. Itano, Kyoungsik Kim, Leo W. Hollberg
We report tests of local position invariance (LPI) and the constancy of fundamental constants from measurements of the frequency ratio of the 282-nm $^{199}$Hg$^+$ optical clock transition to the ground state hyperfine splitting in $^{133}$Cs. Analysis of

Frequency Uncertainty for Optically Referenced Femtosecond Laser Frequency Combs

February 1, 2007
Author(s)
Long-Sheng Ma, Zhiyi Bi, A Bartels, Kyoungsik Kim, Lennart Robertsson, Massimo Zucco, Robert Windeler, G Wilpers, Christopher W. Oates, Leo W. Hollberg, Scott Diddams
We present measurements and analysis of the currently known residual frequency uncertainty of femtosecond laser frequency combs (FLFCs) based on Kerr-lens mode-locked Ti:sapphire lasers. Broadband frequency combs generated directly from the laser

Radian-level coherent optical links over 100's of meters and 100's of terahertz

January 18, 2007
Author(s)
Ian R. Coddington, Qudsia Quraishi, Luca Lorini, William C. Swann, J. C. Bergquist, C. W. Oates, Scott Diddams, Nathan R. Newbury
We demonstrate coherent transfer of optical signals with radian level noise (in a 25 MHz bandwidth) through a series of laser systems spanning from 657 nm to 1550 nm over several hundred meter distances.

Kilohertz-level spectroscopy of cold atoms with a femtosecond optical frequency comb

October 19, 2006
Author(s)
Tara Fortier, Yann Le Coq, Jason Stalnaker, Davi Ortega, Scott Diddams, Christopher W. Oates, Leo W. Hollberg
We have performed sub-Doppler spectroscopy on the narrow intercombination line of cold calcium atoms using the amplified output of a femtosecond laser frequency comb. Injection locking of a 657-nm diode laser with a femtosecond comb allowed for two regimes

A Low-Threshold Self-Referenced Ti:Sapphire Optical Frequency Comb

October 2, 2006
Author(s)
Matthew S. Kirchner, Tara M. Fortier, A Bartels, Scott A. Diddams
We demonstrate an octave-spanning, self-referenced optical frequency comb produced with a high repetition rate (frep=585 MHz) femtosecond Ti:Sapphire laser that requires less that 1 W of 532 nm pump power. The frequency comb was stabilized to a CW laser as

A single-atom optical clock with high accuracy

July 14, 2006
Author(s)
Windell Oskay, Scott A. Diddams, Elizabeth A. Donley, Tara M. Fortier, Thomas P. Heavner, Leo W. Hollberg, Wayne M. Itano, Steven R. Jefferts, M J. Jensen, Kyoungsik Kim, F Levi, Thomas E. Parker, James C. Bergquist
For the past fifty years, atomic frequency standards based on the cesium ground-state hyperfine splitting have been the most accurate timepieces in the world. One of the most accurate, current-generation, cesium standards is the NIST-F1 fountain, which has